Still Sanders, though I'll still vote for Clinton if she's the nominee. With the recent chaos on the GOP side though, I feel more confident now that either Democrat would win the general. Depending on how the FBI investigation goes, I believe Sanders is the safer choice and that it's riskier to nominate Clinton. Some obviously have differing beliefs, but that's my personal opinion.
The FBI investigation will be wrapped up one way or another well before any candidate is nominated, so there's nothing to worry about there.
Probably, though there's still the unknown duration of time between that moment and the moment the DoJ announces what it's doing.