I also have a 2002 31BW-FS with bedroom slide. I agree with your comments (great unit - seldom have problems). I'm no expert, but since you're not getting any replies, I'll tell you what I know.
I understand access to bedroom slide mechanism is from underneath the bed. Raise the end of the bed (to access the storage area under the bed). You should see a removable panel in the floor under the bed. I say "I understand" this is what you do... I bought the unit used in 2006... had dealer check and lube both slides the one time I've had it in for service (3 years ago)... that's what they told me to do to gain access to the bedroom slide mechanism.
BTW, should you ever have to operate the bedroom slide manually, there is an access hole in upper left-hand corner of the front storage compartment on left-side of the trailer (these directions assume you're facing the front of the trailer). The trailer came with a crank and rod for this purpose. I mention this as it somewhat hard to find and tricky to operate... If you're not familiar with it, you might want to do so in case you ever needed to to it. (I haven't... but we all know these things will only work so many times before something breaks.)
Hope this helps. Now a couple of questions for you (or anyone else) if I may:
1) Have you ever had to do anything with the Nev-R-Lube sealed bearings? I haven't... but I'm getting a little concerned given the age of the trailer. Replacements are quite expensive. I thought about carrying a spare, but I understand it's not a simple side-of-the-road repair.
2) Where do you carry your spare tire? Sunnybrook's solution for the 2002 model was a bracket and cover that bolted to rear square bumper... I have a hitch for a bike rack on the rear, and I don't believe there is room for both. It's harder to access, but I wish the spare would ride underneath the trailer (like it does on the later models).
3) Anyone ever replaced the carpet in one the these models? (After 10 years, it's overdue.) Anything I need to know? (especially regarding carpet in the bedroom slide)