Welcome to the forums.
I have a Fire/Cold at 16 and a Mind/Cold at 50.
Your plans should work well. Fire/Cold should make for a great team player and should be pretty good at farming, although not like a Kin most likely.
The set has one major weakness: no AoE heal for the imps. This may make keeping them alive more difficult. Or you may not notice it much.
Rather than the Ice app though I'd be thinking Stone. It's probably not as thematic but you'll be in melee anyway, and could really make use of the heal and extra HP. Barring that, Psi is a good choice for Indomitable Will. It's also hard to go wrong with Primal, thanks to Power Boost, which works great with Cold (despite not boosting the shields) and really helps Fire's limited AoE mezz abilities.
I have one of these in the upper 40s and its been great fun. The -def -res in the cold powers helps the imps hit and hit harder, and the shields, slows, knockdown, and arctic air keep them alive longer. I added aidself and aidother to further boost survivability.
I/O to flavor and you have a fun character. I think my current build is softcapped at range and AoE. I use bonfire for melee timeouts. Added recharge is also very nice in this build, as heatloss is a very nice power. Endurance was a pain until I got heatloss, but then again, I spam the AoE immob like crazy and I like ninja run.
I just have ice breath and ice storm left to pick up. I use sands of mu and nemesis staff often since they hit reliably with the -def powers. I also use keybinds for my shields so that keeping up with them isn't much of a bother on large teams.
cold dom characters really have something for almost any situation. Trollers can make the shields atleast somewhat useful solo. /cold trollers are a great jack-of-all-trades addition for any team.
Thanks for all the input. I'll work on a Mid's build and post it here when I've finished for review/critique.
I checked and my build is only close to soft-capped to ranged damage (like 44.8% or something similar). I chose a very inexpensive route to slot, but it is still a very fun build. However, any +recharge you can add is sweet icing to this otherwise tough troller.
So, for some reason I've had an itch to play a /Cold Dom controller lately. While shuffling through mid's trying to find some synergy between the primaries and Cold, Fire caught my eye. I've always been a fan of heavy AoE based characters (i.e. Fire/Kin, Shield/Electric, Spines/Fire). I felt like not only would a Fire/Cold be a great teaming character, but also a lot of fun to mess around with for farming potential.
My idea was to combine Sleet + Ice Storm + Hot Feet with containment from Fire Cages, all while the imps are running amuck through the group. Heat Loss to keep your end topped off. Hibernate as an Oh **** button. Arctic Fog allowing you to get close without being seen for Cinders while Flashfire is on cool down. I've considered switching Ice Mastery for Fire, taking Fireball, but was curious to how Ice would hold up in conjunction with Sleet.
Now I know it's not going to be able to run through groups like a Fire/Kin would, but I feel like it has potential and would have more of the "Fun Factor".
My intentions were to have a fun teaming/TF character that had some solo farm potential that wasn't a /Kin.
Does anyone have experience with this that can comment? If not, does this idea hold any weight whatsoever?
p.s. I've been playing CoX on and off since the summer of 06' and this is my first forum post :P