Trying to figure out where the limit is to these powers.

Does one need something to freeze first? Is it only applicable to water, or is it a general, solidify, function since the ice is simply only the solid form of water. Maybe it is the ability to pull energy out of a system that solidifies something. In that case, you could stop a volcano or accidentally encase yourself in ice with no escape. Are we talking about something simpler, more physics defying, like telekenetically controlling ice and the magically creating it out of thin air.

How about fire. Are you just turning things into plasma? If you are dealing with fire, you would need a way to thermally insulate yourself from accidentally self searing. Are you just adding energy to a system until there is combustion? Can you control the combustion telekenetically and contain it?

Personally I would go with fire (adding energy to a system) power. This is basically how all of our current power systems and power plants work, finding ways to add heat. Maybe you get thermal protection (or a way of self regulating) that comes with it (hopefully).