Hah, I thought about your wallet/post when I was first building all of this :)

To integrate or build something like this with BitShares, we'd need a JS library like steem-js (which it looks like exists) and maybe a month or so of intense work, maybe more. I imagine BTS has a lot more features that require an active key and would warrant a wallet.

Also - doesn't BitShares already have a GUI wallet?