But in what way is this realistic?

Also it seems your system would result in multiplying the value of population pretty intensely, making invasion a completely loser strat until almost all of known space has been claimed and developed.

Before your suggested change did you mean?  I think that might be the real problem.  When you view the game as us versus x copies of us (but not as good-looking, naturally) then there's some point to the planetary takeover mechanic, but we're supposed to see it as every player growing their civ organically, deciding crucially about strategically situated planets.  Only in multiplayer would that be remotely possible - in that case your statement does not apply before your change, and it's closer to being applicable with it as I've already stated.

yeah I'm mega-against turning solo gc3 into a bureucrat's wetdream which is what this finagling seems to be taking it toward.  would you say that people have a good instinct for working within your alternative system?  I'd say it's steepening the learning curve instead.  yet, to move in the opposite direction would entail creating realistic interaction by the AI.  why not make their simulated emotions logarithmic, as long as we're talkin number theory?

I will admit I feel after 2.5 games played, that starbase benefits should be logarithmic.  or else their cost should be made exponential, somehow.  let them justify it however they like, I don't care

That Elerium shield thingie begs to differ. 100%+ resistance is no joke to invade It always annoy the crap out of me when one of the AI's decide to build that thing. 

I am still badly out-expanding the AI on suicidal with Naselus's IAB mod.  Of course that's partly because I know almost every trick in the book when it comes to expansion.  

Only in the beginning. In the late game God knows what I can produce.  

Naselus is nerfing adjacency bonuses massively.  Which is a pretty good idea.