H264 if you're just playing the movie forward and performances won't be a problem (for instance you don't play more than two 4k movies simultaneously - depends on hardware of course) HAP if you reach performance limits of your machine or if you have to scrub inside the movie (HAP has one jeyframe per frame)
Yes H264 should be good enough. I you have performance issues, you can activate "Use Hardware Acceleration" on some movies (it will move part of decompression work to the GPU) If you have performance issue anyway, you can switch to HAP codec, it gives awsome results.
Worked great! no issues, H264 ran smooth! I kept my bit rate low, at about 8000 so the file wouldnt be too big, also set them all to the same hot key so i could play them on seperate maps simultaneously... .