Sounds like a good idea but, imho, would be little difference than just having all the themes on your sd card and flashing the one you want. Even using the aroma one you would have to reboot to recovery to change it so it would be pretty much the same process anyways. I thought it would be neat though to have an aroma installer theme that would let you choose color and different options such as center clock, AOSP lockscreen, AM/PM remove, etc. But that would be a massive under taking on the themers end because then it would be making a theme times however many colors then each one of those would have to be edited for the different options it would be ALOT of work but it would be very very cool I think.