I don't know much about FCP except that it's a top of the line video editing software. Adding music to a video is a basic, absolutely essential feature for that type of software it definitely does that. Does it do slow-mo, IDK, my guess would be yes and if not there should be an add-on that gives you that capability. Though slow-mo works best when the source video has a high FPS.

Honestly you should ask Sarlacc, he would know for sure. Make sure you tell him I sent you, he loves me.

Have not been on here much. I got it figured out. I just had to restart my pc,then was able to install Windows 7. It's great

So what happens after you restart the system and trying doing the upgrade process again? Seems like you have some windows updates that are waiting to be installed and the upgrade can't continue until you restart the PC to finish installing the updates.