Is it possible if I load one micro SD card with OSMC and the other with Raspbian and then switch them depending on which software I want to use at the moment? Will this not work or cause damage to the Raspberry Pi 2 B?
As long as you do a clean shutdown on one OS before switching out the SD cards, you should be fine. It's how the Raspberry Pi was designed to be used.
That would work fine, as long as you shutdown the Pi. If your SD is 16GB+, you can cram 2/3 OSes onto it using NOOBS. When you start it up, it gives a menu asking which one.