2) Right now, the channel doesn't appear to actually check to see if the Roku is set for 1080p. Might be worthwhile to add that, just to avoid the inevitable support requests.
Yup, I was going to make a post about this in the dev forum later.
I already check to make sure that GetDisplayType() is "HDTV", and exit the channel with an error message if it isn't. I wanted to specifically check to make sure that the Roku is set to the 1080p display type, but there doesn't seem to be a way to do that.
GetDisplayMode() returns "720p" even if you're set to 1080p. I suspect that this is because the Roku displays all channels/menus in 720p, and only switches to 1080p to play video when the need arises.
I'll definitely look into your other suggestion as well.