Ok, good to hear 
You won’t have to worry about any big updates coming for a long time, though I may add some minor ones; primarily with bug fixes. Since I will probably only add minor, additive features if any, the best idea is probably to copy these over by migrating and copying nodes. For larger updates I usually recommend migrating your own additions over to a fresh project, since you know your own additions best. But as mentioned, that would not be needed for a long time, since I’m unlikely to find the time to do serious work on the toolkit until after Christmas.
Yep, though it has been added a bit differently. Splitting up move used to be defined within each unit. It has now moved to be part of the ability system. If you want a unit to be able to split up its move, you design the ability so that it interacts with action points the way you want. If you look at BP_Ability_Move it is set up by default to work the way you are describing. You could duplicate this ability and use it as a base for your own.
Ok, this was a fun little challenge. Turned out to need a few more steps than I assumed. First in BP_ATBTT set the default pawn class to whatever pawn you’re using for your custom camera. You can use the built-in DefaultPawn for testing. Then, disable ActivateATBTT from activating at begin play in BP_ATBTT. Next enable tick events in BP_PlayerController (in class defaults) if you use tick events in your pawn (this is the case for DefaultPawn). Lastly disable the BeginPlay event in BP_ATBTT and instead have it trigger on a custom event, in which you also spawn a grid camera, possess it and run ActivateATBTT. Here is an example in BP_PlayerController_ATBTT in which I go from the free camera to turn based combat and the grid camera by pressing X:
https://i.imgur.com/7UNUDsj.png
Hope that gives you your desired result