Nope, so far most are level 2, with a few 1's and 3's (still pre-Dragon Knight). The 4 in Broken Valley sure is the odd one out.
So far 2 seems best, and pays itself back anyways (2 skillbooks).

Same. But not all chests have keys. Otherwise lockpick would be rather useless laugh.

I always take the XP. Higher level means higher random loot means more money. And useful random items. And power. So not that hard a choice wink.

Thnx.
Btw, I also keep account of my rabbit genocide, and it seems all rabbits from Farglow aren't taken into account for the Killer Rabbit. So I wonder, would the Orbjas be if not triggered in Broken Valley? (not gonna try that though...)