1. It would be very nice to be able to delete multiple SSH keys at once.
  2. It would be very nice to be able to just drag & drop the public key file into the browser, and be done with it.
  3. It would be awesome to be able to see which droplets/services that use each key.
  4. It would be very convenient if I was able to install a new SSH key without resetting root password and logging in with the web console.
  5. Sort of an extension of 4. I guess, but if each droplet had an interface that let you add/remove SSH keys you have on your account, or upload a new one.
Some of these are probably very trivial to add, while others aren't as simple, though each of these ideas should be very possible to add without too much of a headache.
Also; sorry in advance if these ideas are duplicate and/or already possible in your systems - just couldn't find these ideas or features in your control panel right now.