Hi and welcome to the club! Yes, I know what you mean - for me, too, Aurelian is one of the greatest ruleset ever. You'll have a lot of fun wih it, I'm sure.
As for the map: The idea of Aurelian is that the fighting isn't restricted to a certain area but all around the (Roman) world, where ever the need of action had occured. Thus, too, the recruiting system is linked to that idea. Of course the rules are flexible enough to cope with other sampaign ideas. However you will find it quite hard to keep the game balanced. My recommendation is to use it first as it is. To use a map solely to keep track of your exploits, however, seems like a nice idea to me.
The idea to use a commander as a sort of additional adjunct, however, is great. You could "lend" some rules of another adjuncts or invent new ones. I'm interested what you come up with, please share your ideas.