I think the best solution would be to make it more like a Buc-ee's men's restroom with urinals on one side, where they are currently; stalls on the other side, where the sinks currently are; and sinks in the center, where that massive open area (that often also gets slippery for whatever reason) currently is. The largest hurdle would be ensuring that there is enough space for wheelchairs to traverse the restroom.
I like the idea of turning Build-A-Bear into a second dedicated IP shop, though IIRC the Peanuts characters cannot be shown next to non-Peanuts IP so the park would need to choose which to display. One of the renderings for KI Essentials does specifically show a Snoopy bubble wand on a circular rack.
Something to note: The store at the front of the park is the KI Trading Company while the store in Rivertown is the DB Trading Post. Both are fine as they currently exist, but I felt the need to ensure we made the right distinction either way. I'd hate to see BAB go in DBTP because it would get rid of the only large store in Rivertown. It would also feel out of place, like how Panda Express does for some in the Festhaus.