With regards to your GUI question... that is the whole point of a web wallet, there *is* no installation. No counterpartyd to set up and install. You simply go to a webpage, generate a passphrase, paste it into a text box, and click login. Takes all of 5 seconds. Nothing to save or worry about beyond your pass phrase (which *is* your wallet)
This kinda reminds me of NXT - any chance we run into same security problems with that, as they did?
Just need to have the (brain)wallet refuse or complain a LOT about low entropy passwords