rushing fraternity as sophomore transfer

Questions about rushing a fraternity as a sophomore
-Is it harder to get a bid from top tier fraternities as a transfer?
-what's the deal with fall recruitment? online it says anyone besides first years can participate in fall recruitment, so is that the best thing to do as a transfer?
-what is "dirty rush" and is it only for freshman during the fall? would fall recruitment for a sophomore transfer mean that they don't participate in "dirty rush" because they are actually allowed to rush so it defeats the purpose
-also, does anyone know if the club lacrosse team members tend to belong to a certain fraternity?

thanks!