I finally had some success after having a lot of trouble with music on the phone by
1. turning off Connect With Xbox Music, Xbox Music Cloud, all of that
2. deleting all offending songs by actually going through the phone itself, not the computer the phone was hooked up to
3. going over all of my ID3 tags with a fine fucking toothed comb, and fuck no the artist for that track is not XXX feat. YYY, its just XXX
4. after dragging and dropping all of the music back onto the phone, using mpatool to add background artwork
I had to repeat steps 2-4 several times to get to the point I'm at now. It was an incredibly frustrating mess, but I'm fairly happy with my music collection on my phone now. Lockscreen artwork thanks to mpatool is pretty awesome, and I like the live tile for Xbox Music on my home screen. I just wish it didn't go away as soon as the music is paused.
It's important to note that ID3 tag imperfections were not the only cause of the problems I was facing. For example I had an album with immaculate tagging, but once on the phone the tracks would be split into two identical albums, one with the album year listed and one without. None of the tracks had any album year info in any ID3 tag. This problem persisted even if I deleted and re-added the folder containing the album from my phone using Windows Explorer. It wasn't fixed until I did the above steps (except no tag editing was needed).