I made two 10" cakes, both 2" high. Up till now, I've only made 8" rounds, so this is a little bigger than I'm used to. I also used to cut my 8" cakes into 1" high layers and frost each layer. Is it ok to cut a 10" round cake in half or will I likely end up having it break on me? Any tips on doing so? I always freeze my cakes, so I'm thinking it may be safer to work with it when it's semi-frozen. Thanks for any advice.

Do it the same way as you 8 in and you'll be fine.

Partially frozen would be better, but not too frozen otherwise it will be difficult to cut and uneven as a result. Use a cake lifter or a cookie sheet to lift the top layer from the bottom layer. HTH