So here's the scoop. After our room only reservation, I was able to use all three bands per person since we had the triple split stay. However, you CAN NOT get your tickets activated three days prior IF they are part of a package. Otherwise you can with no problem. When I explained to the front desk I read over and over and told by CM reservations I could with a package, she then proceeded to activate the tickets for the parks the next day for the YC club reservation(we were at AoA). She printed me the validation that the tickets were active and said if we had any issues the next day to show the paper. The tickets were for seven days and linked to the second reservation. So no problems there needing to activate for third resort stay.
As for dining credits...they activated after the check in at YC.(as told) We finished them the morning we checked out(fortunately). Meaning if you do not use credits, you can't start the next reservation dining plan. That plan even though checked in at the third resort can not activate credits until midnight of the check in date or until all previous credits are used. Sounds confusing but quite simple. If we wanted to use them and the others weren't finished then you have to ask the front desk to manually do it the next day. The desk at WL was not prepared to handle this situation of a split stay and did not add the dining plan to my bands when checked in. I checked them at Roaring Fork and had each band scanned to review credits. The concierge handled it quickly and efficiently and made sure all bands were activated so we could switch out colors if we wanted. I felt the front desk at AoA and YC were far more prepared to handle questions than WL, which surprised me.
All in all a very painless situation all around. I personally love the bands as did my kids(my 8 year old loved the charging privileges, using for photopass, fast pass etc.) and the whole FP+ system. I guess for an over planner like me and asking so many questions helped a lot too!