You'd need to install 10.7, not El Capitan, and only if, for whatever reason, 10.6.8 can't read or format the micro SD card. There will be no problem. If you rip a CD, there is NO DRM added to the files. You'd want to use an external HD, not iCloud. If you rip a CD, the files are stored as files on the hard drive, which can be copied like any other file without issues. This has zero to do with iTunes, or Apple accounts or anything else like that.