I notice that if one makes a keyquest lobby, one is given the option to invite friends. If one does this, does it switch to a "just for fun" mode with no prizes, or is this exploitable? IE: Your friend just makes sure they don't miss two turns in a row so they don't drop from the game, but otherwise do nothing and let you repeatedly win gold keys. It could be taken one step further with two personal computers and separate internet connections.

Has anyone tried this with, or with success?

I tried completed a few games using my laptop to play myself and haven't had any problems, yet. As it turns out, it's actually faster for me to just play other random people, as my school's high speed connection almost auto-wins mini games, but I suggest this strategy to anyone suffering from a slower connection.

You can play with your primary computer and work on other projects while your secondary computer idles its turns away(as long as you don't miss two turns in a row).
Because of the idling, it is actually slower than playing against someone else, but if you have a slower connection and have problems winning because of it, it may be worth the extra time.
Be sure that you use two different internet connections.