That's a good article, but it does point out some errors in your post.

The compulsory license only covers the the mechanicals: i.e., the production/sale of the record itself. Most of the mainstream recording industry uses the Harry Fox Agency to channel the compulsory royalties. However, some don't, so you may have to figure out where to remit your statutory royalties. This is all you need to sell the "records" on line (provided you aren't letting people hear the music on the website).

As for performance, compulsory license/statutory royalties do NOT cover the performance. Again for most artists, the performance rights/royalties is handled through one of the Performance Rights Organizations (ascap, bmi, sescac in the US). This is what you need to perform (either live or from the recording) in public either on the website, at some concert, or on the Radio. There's no "compulsory" requirement that these rights be issued, though most artists are covered.

All of these organizations have pretty good FAQs on their websites if you want to do further reading.

www.harryfox.com
www.ascap.com
www.bmi.com
www.sesac.com