I don't use more than one type of video at a time, but read up on sequences
Please NOTE that the PPro CS6 screen may look a bit different (I use CS5)
For CS5 and later, the easy way to insure that your video and your project match
See 2nd post for picture of NEW ITEM process http://forums.adobe.com/thread/872666
-and a FAQ on sequence setting http://forums.adobe.com/message/3804341
Your biggest problem will probably be the 29.97 fps 'ATSC' footage. It's just not going to look right mixed with the normal PAL rates of 25 and 50.
That's a BIG problem. I've got pretty much a 50/50 ratio of these two frame rates. Are there work arounds for this? What about posterize?
Try it. But my guess is you'll see a discrepancy between the two types of footage no matter what you do.