Hi guys,
I am surprised you can ride no hands on rollers. That's pretty impressive. For me - I can do one hand, look around, move arms and change positions, but not no hands. I would crash for sure.
For climbing, if you're in the big ring in a 15 or smaller, you can get out of the saddle pretty easily. It's the issue of stability again - i.e. don't rock the bike back and forth, you'll ride out. I have tried numerous 'styles' out of the saddle, mostly, it's a modified sprinting position that seems to be the most stable.
JB