Timmytoe

Based on the video and what they are talking about I would say the shoulders are more closed at address.  

No,  Lots of Practice and mirror/video work so it becomes natural.    How do you know how much shaft lean you have, or ball placement,  knee bend,  wrist bend,  etc.  

You'd have an open alignment of the shoulders.  Not exactly the recipe for solid ball striking.  You'd have to manipulate your swing somehow in order to return it to the ball in a manner to produce decent contact.

I see you are trying to do a one plane deal.  I have an entire “journey” thread about it. It takes A LOT of adjustments.  Check out my battle/trial/whatever it is here…
 

Okay, so let’s looks at wrist cock.   I think your wrist cock is fine in the gif you posted. If you want to copy the swing the you need to learn the entire swing philosophy and not just specific parts or body position starting with grip and setup.  Also find an instructor or material that teaches that swing method. 

Your grip is the first major issue that needs to be fixed. The second is your hands with an iron are too far out in front of you. Fix those before you worry about anything else you posted on positioning or how to do something.
Some suggestions study the Ben Hogan book more on how to grip the club and setup and work on that over and over. Google athletic motion golf grip and setup. Watch those videos and work on that over and over. Lastly if you don’t prefer those options find an instructor online. Some good ones do them for less than $60

That elbow setup that Bryson uses is the same setup that Hogan uses and that you will find a lot of pros have. As you can see his shoulders and upper arms are neutral. The right elbow setup helps with proper arm fold and makes keeping the club on plane. 
 
As you can see in Matt Wolff’s swing he has some similar right elbow setup but has a completely different takeaway than Bryson and Hogan and stay internally rotated all the way to the top so that elbow setup probably isn’t your issue but rather how you are moving the club/body to start the swing and up thru left arm parallel that is affecting your swing or what you are trying to accomplish. Which is why I get back to if your setup including grip that if they don’t match with any you are trying to do you will have issues. Everything is about matchups. 
 
without seeing a swing nobody will be able to tell you what to focus on or where you are having issues
 

Proper sequencing is going to help with getting more power as is strength and speed training both of which Bryson does. Bryson and Hogan have different swings and swing approaches, not sure combining them is an optimal way to go about accomplishing what you are trying. 
 
Regardless of either swing if the fundamentals in setup aren’t correct and sequencing isn’t correct then you won’t be able to emulate what either of them do.  
 
Since you have a focus on Hogans approach which is to not hit the ball left I would suggest getting his Five lessons book and reading that along with watching Bradley Hughes YouTube videos and possibly investing the $185 or so for his drill series and following that. Or find an online instructor like Dan Carraher, Monte Scheinblum, Chris Ryan, Eric Cogorno, TJ Yeaton to make a few and working with them. 
 

By externally rotating the shoulder. Your current positioning isn’t a bad thing. You would just have to externally rotate as you shallow the shaft. 
In all of your posts so far about the swing so far your focus in on the symptoms in a swing and not the cause. You need to figure out what you are doing that puts you in those positions.
 
Thers lots of ways to swing a club and what happens from between shaft parallel and top of the swing is compensation for what happened between address and shaft parallel. 
 
Some questions.
What ball flight problem are you trying to fix?
Are you just leaning the golf swing and if so have you gone to an instructor at all?
One of your posts was about Hogan’s method of swinging? Have you read his book and followed his approach from the book?
 

Could be that you are restricting your hips and not getting any loss of knee flex in the trail leg, could be that you have an improper sequence like using the arms and not the chest/rib cage/shoulders. Not all issues with rotation are do to flexibility. 
 
Have you videoed your swing to see if there’s any faults with your swing/sequencing?
But if you want to go down the flexibility route which isn’t necessarily a bad thing look at meandmygolf, joeyd, golfwod, they have some stretches to help

It’s one fluid motion. The chest rotates before the hip by a small fraction. The entire golf swing is under 2.5 seconds there’s not much time in the golf swing to say x moves before y. The chest is going to rotate about 15* before the hips move then it’s going to be 30 for shoulders sbd 15 for hips, til the top where theres 90/45. The swing is about 1/2 over by time the lead arm is parallel.
 
 

What % of the time do you think you'd use it for partial shots as opposed to bunker/chip/pitch/flop shots?

Jason day has very little wrist hinge while mickelson is quite handsy

I just practise the flop shot using my lob wedge but is there situations where learning it with a sand, gap or pitching wedge be useful?

Personally I see no reason what so ever to hit a flop shot in a round of golf - I don't have the time it takes to hit it well enough to use it successfully - I used to work on it some but honestly the best I can ever remember doing is 10 feet - it was an impressive ten feet because I made a big swing and the ball landed dead but I could just have easily left 10 feet hitting a normal shot with my 60.  That would have been the smarter play, for me.  If I'm in a position that calls for a flop shot I've hit a poor approach and am looking to get away with no worse than bogey anyway - choosing the flop brings all sorts of n umbers in - I'll just hit the 60 to 15 feet past and take my chances from there, no muss no fuss.
Better to use the time working on normal chips, pitches, putting, driving, bunker shots, drinking a beer, things that are very useful out on the course.
That's my take.
But again some people enjoy the challenge of hitting a fun looking shot, if that's you by all means go for it.  I can't quite figure out why you'd want to do it with a less lofted wedge unless your lob wedge were a high bounce 60 that you use for sand play and your 56 was the low bounce one.  That would make sense and might actually be easier to execute. 
 
Good luck regardless of what you do.
 

I just practise the flop shot using my lob wedge but is there situations where learning it with a sand, gap or pitching wedge be useful?

don't believe so.  Stricker is square, rotations based, minimal wrist hinge.  Siechmann is a bit open, more swing than rotation, and more loading with the wrists.  

To me, a pitch shot is a relatively short shot using something similar to full-swing mechanics.  A knockdown is generally a longer shot where the set-up and swing is altered a bit to produce a lower ball flight.  Generally, knockdown shots are done using a bit more club than the distance might require, and slightly reduced swing speed, both of which tend to produce lower ball flight and reduced backspin.  A pitch shot might be done using the full loft of the club, and might be intended to produce significant backspin.

Ah yes it's actually the newer f9 cobra which have different lie angles [i read that on wrx anyway] 

іvе rеаd thаt Cоbrа chаngеs thе lіе аnglе fоr еаch club. Thеу hаvе thеіr rеаsоns whіch Wіshоn dіsаgrееs wіth

It most likely has toe hang based on what I see. To see toe hang, balance the putter on your finger or lay the putter on a table where the head hangs off the edge and the putter can freely rotate.

If the points straight up (heel and toe are at the same height)it is face balanced. If the toe end of the putter is higher than the heel it is toe up, and if the toe is below the heel then it has toe hang. People will often classify the amount of toe hang by degrees down from parallel or a clock number. So if the toe points to t ground it is 90* or 6 o’clock. If it is halfway between parallel and the ground it is 45* or about 4:30.

Toe hang is largely influenced by where the shaft would intersect the head if it kept going past the hosel. More toward the center the more face balanced it would be. All the way at the heel would product a full toe hang. Toe hang can also be influenced by the putters CoG; meaning I can move weight toward the heel to decrease the toe hang

Generally loft specs for putters in box sets aren’t published. If
I were to guess I would say 4*. But with tolerances it could be 3 or 5. Knowing a spec value isn’t really important; you need to put it on a loft/lie machine and see what it actually is.

Phil stands with the ball off of his instep [of his right foot]  From this guide when he used conventional grip, he delofted the putter just before swinging it https://youtu.be/GhzY7TIMnMU?t=348 does he still do this with his claw grip?

Phil stands with the ball off of his instep [of his right foot]  From this guide when he used conventional grip, he delofted the putter just before swinging it https://youtu.be/GhzY7TIMnMU?t=348 does he still do this with his claw grip?