Honestly, the biggest reward I would like to see for donations is that the site is not run at a loss. SneakySly has been great to cover it thus far, but for all the work he and you guys do, none of you should have to be paying out of your own pocket for running the site or for the prizes for leagues and whatnot. I've often been somewhat amused by the idea that if the site or ANRPC got to that point, people could just order kits from you guys that had promos and such things.
The next important thing is just helping explain the theory behind the game (or why stuff works). Either coaching streams, articles going over certain ideas in the game (like early / mid / late game), or even getting any of the excellent players on the site to just talk about deckbuilding more.
And yeah, there's no reason to pay for editors. I am currently unemployed, and would be happy to help contribute to a site I frequent often by helping to edit / proofread articles (and so would a few other people, I'd imagine).