It's time to Terminate it. (Please don't be baaaack.)
I love watching Arnie (which is why I gave it a shot), but the script is more than absurd, by it's own definition! SPOILERS:==> Let's start with the screaming Elephant in the room: The instant the Terminator is sent back, John Connor would be gone, IF he had been prevented from being. They don't have to "hurry". They're now already in the future, from the "new 1984". i.e. Their future would have changed instantly from the time the Terminator was sent (from their perspective), in any way it had been altered. (To quote the film: "What do we want? TIME TRAVEL! When do we want it? It's irrelevant!" Exactly.) There was an easy way to avoid that problem, but the writers couldn't figure it out... However, let's look past that one. (No pun intended.) Then, there's the past & future that had already been changed, when they got there: 1984 is different; 1997 is different; 2017 is different. Remember, Kyle Reese was originally born AFTER the "Rise of the Machines" & the "destruction" of the world. Now he's 13 when this is going on, which changes EVERYTHING, including the glaring absurdity of a 3rd example: The last scene (or "thing he has to do"), where he goes to talk to himself as a 13 year old, and gives himself that "important message", is completely irrelevant & therefore unnecessary! All of that has already been changed, as he is living a "normal life" with his family, at least into his teens.
If all of that isn't enough, John Conner is completely & totally out of the picture (so to speak), as he was originally born in 1984/5, and now wouldn't be born (even if the two of them do get married & have kids) until at least 2018, making Kyle Reese at least 14 years older than him! Of course, this is completely moot, given the fact that those sperm are now long gone, as they didn't play things out from the "first time" in 1984, so John wouldn't even exist! Yes, as stated in the film: the past & future were completely changed. BUT, the film then seems to disregard that in several scenes which are now nonsensical, as the 4 examples above show. i.e. the film can't even be consistent with itself. Come on guys. The writing could easily be better than that.
Last but not least, of course, is the persistent Political Correctness Follywood wants to shove down our throats. But I've seen worse. : )