I don't quite follow the sentence structure of your 2nd question. When you say, "in the same manner that they embrace theism, who is the "they" of which you are speaking? Are you asking if atheists wish to force believers to reject their long-held beliefs and become atheists? If so, I would have to answer, "no". Even the most vehement of atheists in the West don't (as far as I know) advocate the forced conversion of Christians.
As for the first question, I think very few atheists are active in the "pro-atheist" movement. Heck, there's a lot of social pressure not to even admit that one is an atheist (although that has lessened considerably in the last 40 years). I think most atheists do, in fact, simply wish to be left alone when it comes to their lack of belief.
I will freely admit that most of the "Nones" (atheists, agnostics, and those indifferent to religion) trend left-wing in their politics, although there's a substantial Libertarian/Ayn Randian wing. I certainly lean (not all the way, mind you) in that direction myself.
I had to read that sentence a few times myself to figure out what I was trying to ask; but your understanding of it was correct. Nevertheless, I sense that like any other movement, the goals of the the activists will shift as their philosophy become more acceptable, and eventually, they will want believers not to believe. And Im not making that statement in any negative way; I simply think its reality.
Nevertheless, as a traditional Catholic I pray that the Modernist bishops of our Church speak out in a much louder voice against atheism than they ever did against homosexuality. The results of their muted response to that sin is all too evident today.