if you use itunes as your primary media player, which in my opinion you should, (Bill Gates who?) then in Setup (top right) make sure you have itunes checked. Don’t know if this will solve your problem but works for me as I have itunes make a copy of imported tracks, then I just delete them from my music folder ect. As for the BPM you need to analyse all your files (takes a while depending on the size of your library) then right click the tab above the tracks and make sure BPM is checked. If you don’t wanna fork out however much for mixed in key ect. I recommend downloading Keyfinder for mac, Beta for windows. You can then write the key to the file and then this will also show up in Serato DJ.
Hope this helps 🙂