Well honestly I don't think big bang exludes "god". The thing I don't agree though is the sudden creaton of everything as you see now. I'm more inclined to agree that "god" or whatever had a hand in things that created stars and from there on we have physics and evolution taking over.
You can see species die all the time and become extinct, plus there is there are compeling evidence of other species and their veriaty and their extinction at some point in the past, but you still see so much veriaty of species. So ether god created an overpacked earth and stuff just keeps on dying or he is replenishng them one by one without us noticing it, or maybe all this life is just taking it's natural course and regulating itself. Some die, adopt or florish with acording to the changing enviroment. And we humans are not imune to these things and we are in the same pot as everyone on this planet.
I love comercials and marketing campaigns about "saving the planet". Damn, planet doesn't care about us, we are just another species to them, and if we don't adopt we will probably have the same fate as the dinozaurs did or like any other species that thought they were the top dogs on this rock.
And your view on begining earth and primitive life is a bit summed up, there is trillions of years and so many other things that happened between some of the stages you said. And considering what we know about star formations today it's not that hard to imagine how the earth formed, it's really not. On the other hand, to think that it just poped up from nowhere is a bit trickier.
Imo evolution doesn't disprove god and the same is other way around.