The idea of "all author themes in his profile" is exelent, I thought of it too.

There is an other feature that is missing in the themes section: "the updating feature".

As it is now, when you make un update you have to resubmit it. This makes the site data base grow uselessly (bigger data base means, more to pay for extra plce on the server), it also makes the searching for a specific theme more dificult and finally it may confuse peapol to have many diferent versions of a seime theme.