Can I activate a locked iphone with a sim that is not activated on its own network?

Basicallly I have an Iphone that needs to be activated, and I just want to use it as an ipod touch. So anyway i don't have my old sim card anymore and have since changed to another network, I have ordered an unactivated sim of my old network online. Can I use this to activate my iPhone without having to switch network

Yes, you can.

Yes more than likely it should work.