1. In answering for myself, Fedorov was the better player. In terms of Wings fans in general, I wouldn't be surprised if more said Datsyuk, for several reasons: he didn't have a nasty exit from the team, for a long time now (at forward), the team has been him and Zetterberg, there were more greats around in Fedorov's day + timing thing, Datsyuk's more current.
2. Fedorov should get in fairly easily, but his offensive stats tailed off (under 1ppg, under 500 goals), but he was better all around than anyone + playoff stats are good and he has the major awards to back him up. Also, being the highest scoring Russian in league history will help. Ovechkin will likely pass him, Datsyuk won't, but either way, Fedorov will have held that title for many years.
3. I'm honestly not sure about Datsyuk getting in. Then again, it's always hard to say. There are worse players in than Datsyuk, but there are also better players that haven't made it.