I dont know what you are talking about the 1080p not looking like 1080p. But for the 60fps, you need to convert it to 29.9 or youtube will do it for you and youtube isnt the best at it =P
You should also record at 30fps (or 29.9) because the more you have to mess with the video the worst it will look. So if you dont have to convert the frames so much better. Recording at 120 FPS then compressing it to 29.9 is not going to help you. It will make it take a lot longer to compress though, and your RAW files will be HUGE!