What is the decor in the master bedroom? Can't consider those until we know what the bedroom is like, as the two should coordinate. As far as the style, definitely the second. The first looks messy to me, tho I know that style is popular.

If you can post a floor plan that really would help. It would be a shame to do anything that would obliterate those windows and that awesome view. Your shower must be deceptively big if you are considering adding a pool bath. A pool bath is a great idea. If you do add the pool bath I would certainly eliminate the door to the exterior. Will check back to see if you have been able to post a floor plan and will comment further if you do.

So the bed stays where it is I think the four-poster bed doesn't work in this particular situation. I would replace the headboard with one that is upholstered, low, and simple in design to allow more light from the windows in the room. I would consider a 'bed crown' or corona to address the window treatment and the bed at the same time. These can be as elaborate or as simple as you like. ( see an example of simple short drapery rod used to hold the drapery panels.) Or the crown can be a cornice piece to hold the fabric in place.

This one keep all the plumbing in the exact location with the exception of having a double sink vanity. I like 5'0" deep closet for ease of movement but 4'9" is doable. If you do so, you can get a 6'0". I think I prefer a 6'0" vanity because you have more counter top and wider drawers. You could also go with a 5'9" custom made vanity. The shower is curbless with a curtain. That should give you 16" more floor space when you shower (flat space in a tub is about 20" wide). Below is a picture of a curbless shower with a glass, I would put a curtain instead of a glass. Note how the same floor in the entire bathroom makes the room feel spacious). I would not recommend barn doors for your long closet. Usually, there is a wall behind the barn door when you slide it. You don't really want a wall as you want to have easy access to the full length of the closet. But you could have them if you really like then but you would need to mount them on two rails (similar to regular sliding doors) and they would require more space than the regular 4.5" thick wall. Personally, I would make two 5'0" wide closets with 4'0" double door for each. In this layout, the 2'4" deep closet (wall included) is split in half (1'2" space stole from bedroom and 1'2" space stole from living room).