3. Customizable length means you can change the length of the custom maps
you mean the height?, that's already possible
No he means the length, but this was already proposed once and will never be implemented.
The same counts for his other ideas.
2. Option to upgrade units means that you can use resources to upgrade specific units, athough their ammunition would cost more. You might also be able to upgrade structures.
You can actually already do that, the needed resources are Technytes, so I don't see any reason for further weapon or structure upgrades.
1. Hero units would be units that
a. You could only make one of, although if they die you can resurrect them
b. Gain exp
c. Have unique skills
d. <Insert obvious stuff here>
Not gonna happen, the beauty of this game still (moreso in CW1) lies in its simplicity. Having too many possible units of which one is better than the other is just plain unnecessairy.
Btw: You can already limit the amount of units you can build of one kind to one. Combine this with a dark beam or Conversion Bomb and you've got yourself a powerful hero unit.