I'll be honest...I'm scratching my head figuring out why someone would want to do what you want but...I'll toss out some thoughts I hope you find constructive.
I think the problem will be that finding something with what you are looking for will be smaller and thus less storage...kinda like a cat chasing its tail...you don't get to where you want to be in a straight line. There are some conflicting goals that have to be worked out. Even after removing the bed, trying to get a larger bathroom and more storage seems to clash with a smaller RV's ability to do that.
It would sound like a Class C with the bed room gutted and sleeping over the cab would be the answer based on what you have said regarding sleeping but then you get a smaller bathroom.
To be honest, you might have to find something like a Class C or a very short Class A and then gut most/all of it. It will be difficult to go smaller and increase the size of a bathroom in any floor plan I've ever seen.
I was going to ask if you have you considered "remodeling" your Baystar? After I thought of that I think that could be very unwise. That kind of re-modeling of a fairly new coach would destroy the resale value. So...I guess any project you do needs to be on an older RV where resale value is not going to be a major concern.
Don, Sandee & GSD Zeus. Gardian Wings earned are GSDs Gunny (7/11/15) & Thor (5/5/15)
2006 DSDP 4320, Spartan MM IFS, 2013 CR-V, Blue Ox Avail, SMI AF1, Samsung 197R Refer.