We have been told, by Disney bus drivers, that luggage is not 'supposed' to be allowed on the buses. I can only assume that is true for the monorail and the boats.
If it were me, rather than having to juggle those bags on the monorail (if you're allowed on with the bags) I would just get a cab. One person could take the cab while everyone else could hop on the monorail and meet up at the CR.
As for Disney moving the luggage....never again for me. I've done it twice now. Once from BCV to POR and again from BWV to POP. Both times I handed my luggage off, at 8 am, with a very nice tip. I was told not to expect my bags at the next resort until the afternoon...mid afternoon is what the Bell Services guy at BCV told me. When I started asking about my luggage at POR, around 3:30-4, I was told it wasn't there! POR luggage people finally called BC Bell Services. Seems BC was too busy that day to move the luggage! About 90 mins later, I again asked...nope, nothing yet. Finally, the POR luggage folks told me they would just bring the bags to my room, I didn't need to wait around for them as usual (they do like a tip you see!!). They were incredibly nice about it.
POP wasn't too concerned about the baggage delivery. They told me to just head out and the bags would be in my room later on. Well, this was at 4ish. I had checked in hours before. So, off I went and when I returned, my bags were in fact, in the room. It was about 9:00 by then.
Nope, I'll move my own bags if doing a split stay again. It takes way too long to get the bags, and Bell Services people just don't see what's wrong with that.