Yep, "Clamp" would make sense in this case. :) It appears that the first issue is a strange side effect of some changes I made to the script parser - the added complexity (and therefore the time it takes to parse) for some reason causes the engine to "hiccup" and do some weird things. I believe this may go away once I make some optimizations. Going forward, scripts will be pre-parsed during the game export, something I really should have been doing in the first place so there's minimal delay when triggering a script during the game. This may even help the animation sync issue.
Also, I was going to ask if you would be able to just put all 4 components of the chest into one 32x16 object, but then I realized that I think I may have broken object placement in the Map Editor. Theoretically, you should be able to just make your chest into one 32x16 object, and then it would span 2x1 tiles when placing it in the Map Editor. I had it that way at one point, but it seems now that it's just centering on one tile instead of spanning it properly across two tiles width-wise, at least visually. I will get back to you on this one. :)