The poster is asking if you can get upgraded successively: Balc->JS-> GS or higher. Royal up is one time upgrade from x to y. Pre-COVID, once you won and got your new assignment, some have reported getting a second offer to bid higher y to z - that is now gone. Once you win, you are stuck with that.
No escalator on the ship but there may be one in the terminal.
Same as embarkation.
There's an official time for self-assist but typically you can leave whenever you want (though they want you out of the cabin by about 9AM at the latest).
You can leave directly from your cabin or from anywhere else on the ship.
Boarding is likely to be at least 30 min before that. Getting the Seapass card and formalities between sailings might take a while - don't book anything too soon after arrival.
Post #6 seems to indicate otherwise. If you look/read enough, you are likely to find exceptions to just about any RCI policy - though I think the one about the ship sailing on water is an absolute.