How hard would it be to reframe this bathroom? (Pics)
Hard/Difficult is a relative term...lol Are you planning on doing this yourself or not?
Your "current" pic is how my bathroom was, with the exception of I already had the wall in place that you want to put up.
First thing, the wall between the toilet & vanity isn't a load bearing wall so that won't come into play. It won't be too big of a deal to remove the wall, just keep in mind is there any electrical in that wall that needs moved?
Then adding the new wall with a door shouldn't be that big of deal provided you know how to frame. Personally for me the getting the drywall seems too look decient would be the hardest part, but then again I hate drywall so.....
With everything you've mentioned keep in mind here is a list of things you need to know how to do or not be afraid to attempt:
Shower/Tub - plumbing work (cooper soldiering or pvc & cement), installing the tub & surround (tile or plastic 3 piece surroud)
Wall Removal - drywall, possibly electrical.
New Wall - rough framing, drywall, hanging a door, trim work.
Another thing once you remove the wall, what are you going to do about the flooring there? Are you going to put down a new floor in the tub/toilet area and let it meet with the carpet or a whole new floor?