You're welcome to remix this stuff -- most of the mixes hard-pan the guitar to one side and the vocals to the other side so you can easily chop them up into parts for remixes. Sharing is totally ok too. All songs are under a Creative Commons Attribution-Sharealike 3.0 license which means do what you like as long you don't prevent anybody else from doing what they like too. Oh yeah, and you have to give us attribution.