Yes it is possible to use to IDs. You just have to log out and log in whenever you want to change them.
As for creating an ID with no payment option this can be done. There is a tutorial on the apple support site and if you can't find it on there this topic was brought up a week ago so using the search function on this forum you should be able to find it that way.
Proud owner of a 32GB wifi iPad2 iOS5.