I find it impossible to worry about things like gaining an advantage over my opponents because I just love building all those little cities and agrarian centres and things. Playing to maximum efficiency I could fill all planets with mineral megaplexes and stuff and probably slaughter the AI, but then where would all my ppl live?
In my current vsAI game in Proportions the Drushocka glassed one of my worlds and its moon: total casualties were a half-dozen ships, and about 9 million pop. I didn't even have a completed facility there. Not much of a loss in standard se4, but I was so FURIOUS- I really build up a relationship with my empire in Proportions.
All the military stuff becomes a bit of a sideline for me. I guess really I'm a sim-city guy at heart.