No problems :)

So when I would try to transfer my STEEM out, I'd get a message saying something along the lines of "You have exceeded your maximum bandwidth", which I can only assume means that user actions are rate limited based on Steem Power, and that I didn't have enough Steem Power to do... well... anything. Perhaps if I'd waited long enough I would have been able to do things again?

After fully powering down, I was not able to transfer my steem, power up (I forgot to mention this in my main post, so I'm glad you asked) cancel any ongoing power-downs (although this gave a different message, something along the lines of being unable to transmit the message) and those are all of the things I tried.

I read a couple of posts from other people after searching a bit where they said they had friends who were unable to even upvote or post, but I didn't try either of those things.