CR2. That's funny, my company has similar thoughts like yours!!
Lets face it, there are belly carriers flying everywhere these days. If you're going to design an aircraft to be a freighter, surely you'd want it to be able to carry outsized cargo? To do this, as you've stated, I agreee that the nose door & large side doors are mandatory.
I haven't really been up to date with the A380's development, but one would've thought they try to be innovative to attempt to capture some of the 744F's market. By that I mean something like an inhold system between decks or the like.
At the end of the day though, if Airbus don't take some sort of initiative, someone else is going to take the AN124 platform & turn it into a potential 744F beater!