bitcoin price doesn't look like it can go down to the 220-240 USD range again it has gone up and it is staying up so far. there is no reason for going down.
it depends. if they somehow manage to seize his stolen coins, then traders directly anticipate on that possibility. but then again, what's worse, him dumping his coins on the market, or his seized coins get auctioned.
I guess it is more likely that those coins have already been sold long before previous ATH, either by himself or in case they were hacked by the hacker. It will have minimal influence.