My only 50 is an Ice/Thermal. You are correct that it is a very varied set capable of doing a number of things. Overall, I think your set looks very solid.
Comments:
-I'd swap Plasma Shield and Cauterize. The shield, IMO, will do you more good. You will miss Cauterize, but you will still have Warmth to work with early on.
- I'm not the biggest fan of Hasten for Ice. This is a personal taste thing. I get a lot of use out of Air Superiority in that spot. If you have vet attacks, your experience may be different.
- I'd change the order of the epic pool to Ice Blast > Frozen Armor > Frost breath > Hibernate, and drop Ice Storm altogether. Ice Storm is an okay power, but lasts 15 seconds and is on a 120 second recharge. Hibernate is a great power, but only really needs recharge speed enhancers (3 slotted max) compared to Frozen Armor or Ice Blast which benefit from more slotting.
- I agree your decision to take both Arctic Air and Shiver. Combined you should be able to cap the -Recharge of +4 enemies.
So I want to try out an Ice/Therm all of the way to 50, as it seems like the most "jack of all trades" combo for a controller besides rad, which is my sort of playstyle. Anyway, here is the build I am planning on, which I would like to have criticized and/or changed in with suggestions:
1) BoI/Warmth
2) Frostbite
4) Fire Shield
6) Arctic Air
8) Cauterize
10) Hasten
12) Ice Slick
14) Super Speed
16) Hurdle
18) Health
20) Stamina
22) Plasma Shield
24) Thaw
26) Glacier
28) Shiver
30) Forge
32) Jack Frost
35) Heat Exhaustion
38) Melt Armor
41) Hibernate
44) Frost Breath
47) Ice Storm
50) Frozen Armor
Comments? Suggestions?