The only physical limit you mention would be the missing USB stick support. There aren't many phones around with room for a full-size USB connector, but maybe that could have been solved with some kind of converter. But the microUSB connector is used for charging, as per the new, international common charger agreement. I more and more believe the idea of using microUSB as the common charger type was a huge mistake, as this limits what can be done by same connector (ref. USB consortium).