At this point we are not going to get that granular with flags; however it has been something put in the development queue, just no promise of it being worked on at this moment.Also noted another "bug" I guess. The little flag under the avatar states that if you want your state flag to only enter the state. Well I put just my state in and it says to give a valid city and/or country. Well, I assure you Texas is a valid state. It seems to demand the suggested Texas, USA but as you can see, that only gives the USA flag, not the state.
And yes, Imgbox is currently not a supported GIF hosting site, this is something we're working on resolving.