I know that emulated runs aren't accepted, but are there any significant differences between running LM through Dolphin? A couple of friends just want to watch me practice sometimes and since I don't have a capture card, this might be the next best thing. Are there any differences that would make practicing through Dolphin a bad thing?

r pumping will be off because the game natural lags a little when a boo is in the room. (not all boos do this but most) so yeah it could effect you on that but other than that its perfectly fine :). Also dolphin is not allowed in runs because none of the rooms lag but on console i would say a good 1/6 do so that's why dolphin is illegal.