I don't think I'll add too many default counters, at least until there's a base combat system. It's easy enough, using persistent global variables, for world builders to create their own where they are relevant. For instance, Protea's dungeons use an HP counter, and there will be a desert area in which you will have to deal with persistent thirst. There isn't really any reason to carry information like that between worlds, (most worlds would just have a healing area near the entrance anyway) and it would get in the way of the 'free exploration' theme.
I might make an option to tie a numeric variable to a visible meter, though. Right now, there isn't any way of checking a variable without running a function that displays it somewhere. (Although some clever use of creating and deleting sprites in a row would be a way of getting around this in the meantime).
While making different kinds of interactions would be simple enough, I always found games with different types of interaction more distracting than fun. 99% of the time you're just guessing which interaction is the 'right' one to progress the plot, or checking what kind of wacky easter eggs the programmers have hidden in a particular 'wrong' interaction. It's probably a holdover from old text-based adventure games where you would need to examine things to figure out what they are, which would explain why it has largely disappeared in more modern games. A single button to talk to friends, attack enemies, interact with machinery, search cavities, and examine interesting inanimate objects is enough, I think. And BW already has two (checking and touching). Using items might be an option, though, once items become a thing.
As for the 'starting' areas, that's all up for change. I'm throwing together a bunch of mini-worlds just to see what 'sticks', and I guess whichever ones work best will be placed near the beginning room.
You can make persistent 'looping' effects by using a 'master' sprite that has a function that calls itself when complete, and you can target the player sprite's position with a 'get _x of *' or 'get _y of *'. Custom animations are planned, but in the meantime you can trick the game into animating a sprite by creating and destroying sprites with different graphics.