Is there a way to register my RME on the main site?
I bought it used a year ago, my friend who I bought it from bought it used off another guy a year before that…
Not sure if someone else has registered and left it or something… but is there any way for me to register it? Just thinking for legal purposes later on to be safe.
You can’t register a product where this has already been done. I did register some of my second hand 'foogers, more just to get stickers than anything else 
as I had no receipts. One sticker received for all of my gear (most of it new).
You can register it on the phone as it has to be registered to get an RMA for service. (I just did this with an Etherwave I’m getting repaired and updated.)