So did I just create some cashu tokens with a reserve backed by my Alby Hub (running on a raspberry pi zero in my closet) and now I am pasting it into a nostr event, broadcasting that through some relays to you where you get it and now can claim it.

Do whatever you want with it... If you send it out to a lightning address for example the reserve will do that with my Alby Hub in my closet will do that.