Personally I would not remove the bathroom, certainly not before using the trailer for an extended period. We never use the shower ability of our trailer, preferring campground showers over small wet trailer showers.
Over the years we have met a number of people who have turned their bathroom into storage space, generally without taking out the toilet. Usually I'm amazed by what they store in there.
In our case we have developed other storage volumes in our trailer. There are plenty of ways to increase the storage space without removing the bathroom.
One way to increase the storage space is to use available space more effectively. We have done that by adding 5 pullout drawers and adding a two drawer pull out pantry, again all in existing space.
Another way is to add secondary space around defined storage by sub dividing little volumes, using up little out of the way corners. For example we added two pull out drawers under a dinette. Behind those drawers we subdivided the area adding a wine storage area, a space for a lantern, and a space for back up meds. Beside those drawers is a location for a drill, a crock pot and an electric heater, all under one dinette.
Each cabinet/dinette is like that... a primary storage component surrounded by fitted space for smaller items. We have similar small storage spaces under every cabinet.
Besides using existing space well, we have added space. For example, one end of the couch is tucked in behind the bathroom and is unusable for sitting but usable for lying down. We took advantage of this and built a large storage space over the couch as deep as the bathroom and almost as wide. This added six 27 inch deep shelves.
Similarly we built a full width over the dinette cabinet.
Lastly we have added a lot of outside storage volume. We have a large rear bumper box for all those things that really belong outside, have two large plastic fence posts under the bumper box, one for a sewer hose and a second for plastic poles. As well we have 5 plastic storage containers under the trailer for low frequency used items, like tools, extension cord, ......
If you're interested in some of these possibilities go to Preparing a 1991 Scamp