1) do characters have any sort of default equipment?
or have they to buy starting equipment in Town before the first adventure?
2) when do you erase surplus equipment?
in other words, can characters try to sell non permanent items?
I think that's all for now
By default, characters have to buy equipment before their first adventure, although an alternative is discussed in Donjon Starting Equipment (http://www.indie-rpgs.com/viewtopic.php?t=3619&highlight=donjon+equipment).
As for selling non-permanent items, there might be a way to do that within the adventure, but otherwise, there's not really a chance as surplus equipment is erased before an adventure, and characters usually start in Town at the beginning. If your character can get to someone who'd buy his stuff before an adventure is over, then feel free to sell away.
Quote from: Clinton R. NixonIf your character can get to someone who'd buy his stuff before an adventure is over, then feel free to sell away.
I can just see the ability now... "Find wealthy merchant"