Archangel a lot of the ME3 powers will still indeed work, however there a few that would probably be denied. In particular things like bioticly teleporting or anything involving a sword - generally the later multiplayer powers.

Now that i've solidly figured my own character out (he's still going to be a Salarian hitman) I can hopefully get him up today. Also Derv, will my char still count as a returned one even though i'm making a new char? (But I personally am returning for those that don't know...)