yes, you have to base it off a normal hero, but with an enhanced editor, you can change the model, sound set, image icon, everything so it is like a brand new hero
yea the only way to make a hero is to base it off another hero, then just change the stats and stuff.
but i think that there is a unit editor that u can change normal units into heros by adding stats, but i havent used it that much but i know it can change units into heros. i think that it is still in the DL section.