Never a problem at any house with the closet access from the bathroom. The toilet has never been close to the closet. Separate WC, too in 4 homes I've lived in (3 of those I had built). My current renovation, there is no separate WC, but the toilet is 20 feet away from the closet. I have no closet access from the master bedroom because that would require 3 doors (entry, closet, bath) in the master.

This is just my 2 cents, I'm certainly not a contractor. I would get rid of the shower and shift the vanity over to the right so it's in the middle of the wall. You should be able to do so without having to move the plumbing. I would also make it a good enough size so it can hold your linens as well. But not so huge that it looks ridiculous. I think building a closet in that corner won't look quite as clean. You can save that money and put it towards the vanity and working on the rest of the bathroom. I also think you can totally get rid of the bathtub and put a big shower there instead. Would be pretty great to have a spacious shower. You can do the combo tub/shower thing but it won't look as good obviously. Hard to make style suggestions without knowing what the rest of the house is like. For some reason though, I do picture darker wood flooring and white walls. Not so sure how wood flooring holds up in a bathroom though.

I much prefer the closet off the bath and easy access from the closet to the laundry. Ours is a walk though closet approx 15' x 7' 6". Doors opposite each other giving DH a space of a bit more than 5' x 7'6" and I have about 7' x 7' 6" on my end, so basically two decent sized, but not overly large walk in closets sharing a 3' walk through between the bath and my office (but steps from laundry). DH slept in this morning. I showered and got ready for the day, put up laundry, and dried a load of towels and put them up all without disturbing DH. During the day, I most frequently access the closet and master bath from my office. Very convenient.

This would make sense if you had no other bathrooms on this level, or even had one on this level and wanted to add a half bath. But, it doesn't make sense to have three baths so close together. I don't think it will help resale and could hurt to eliminate the hall closet. Here's the main issue I am curious about - what do you not like about guests having to use the hallway bath? Figure out what bothers you about that and see if you can come up with a plan to address that issue. (For example, do users leave it cluttered or a mess and you don't like guests to see that? If so, can you add a different kind of vanity or more storage organization?)