When I brought my calls home, I clipped one wing.....after they got settled, I let them out when I was home to monitor. Now that they molted and have new feathers, they fly, but only from the pen to the yard and around the yard. (one of them is a little fattie and doesn't fly real well). They stick around just fine. The black one that I got this summer is an excellent flyer- flies at me and does the u-turn back to the "annex pool" and lands right in it- just like a pro.
I wouldn't be for pinioning, just because I figure them being able to fly gives them a quick escape, should they need to get away from something fast. Guess that depends on each situation. Dunno about migrating. They seem quite content to stick around but I live in the middle of a forest, so maybe they think that's all there is.
Personally, I like to watch them fly and they think they're bigshots, flying around the yard.