Yeah. The minimum specs should be bumped up to at least a Core 2 Duo and 4GB of memory. I feel sorry for anyone still using a Pentium 4 for anything. Lol.
Expect sims 1 and sims 2. Well i cant judge sims 1 since it was like the first sims game ever and gay marriage even mattered that much.
Sims 2 never had it either.
True in the original Sims, 2 Sims of the same gender can only move together but not marry each other, but in the Sims 2, 2 male or 2 female Sims can marry exactly like in Sims 3.
Gay marriage will most likely be implanted. Marriage hasn't seem to be that big of a subject now that Sims 3 pretty much filled all those gaps. While EA isn't a good company, yes, I doubt they would sink that low and strip out gay marriage from Sims 4 in the middle of a civil rights movement.
I wouldn't really say there is a civil rights movement happening right now, just that more people who are tolerant and not terrible people (cough ukip (pls dont win election)) are gaining positions of power in countries around the world.