Hm, this is a difficult question, since this is mostly addressed to you I guess. I mean, where would you like to take this game?
It looks like an RTS but with static elements which does not give much of gameplay variety, you'll just have to overpower your opponent. Besides it looks like the current economy system has positive feedback loop. By that I mean, that the one who takes advantage from the start in terms of resources, will only grow it.
Dunno, again, those are just my assumptions on your theoretical plans.
In my fantasy, this node system could be a living moving organism. Or organisms. This would be really cool and fresh :) I guess. Then maybe you'd want the placing of the nodes to matter. Maybe there could be some gold ore on the map, where you should put your miners. All of that stuff.
Sorry for a bit chaotic reply. I'd made a better one if I understood better what you are trying to achieve. Would gladly discuss with you further.