Mote still works for Meph (which is stupid, he needs teleport) but unless you or your merc can tank him this is a good option. Andy is actually a tuffer kill in my opinion as she come at ya pretty hard and the poison can be nasty when you switch to MF items if you have lower resists that way. Only way to keep Andy still is tank, so u will be forced to take about half her life with Fireball only which will do it.
Now, IMO cold is the best way to go with both these bosses. First most everything in Andys lair is FI and there can be 2-3 bosses in there and many times nasty mods and if you mix them with Andy you can be in deep. Cold kills everything in that room and of course slows them. No HF Merc can slow for ya also.
Meph, well its easy to avoid anything but Meph so fire or cold will do fine.
Only way I would speciffically make a fire sorc for MF is if I wanted to run Shenk/Eldrich as well as Meph and Andy, so if Meph and Andy are your only targets go cold. BTW, Pindles minions wiht him are FI also, the ones outside are CI.
IMO all around cold is the best choice for runs like this but Fire is workable.
I kill meph, shenk, elrich and andy just fine using only meteor + static (and one orb to slow em down) but then again i have insane defence (upgraded skullders, ss, defiance merc + shout),75% block and 2k life.My sorc can tank pretty much anything exept fanat or pindles minons. Ofcourse not anyone has the possibility run 2 diablos and give yourself bo