Yeah, that sounds about right. I believe Kerbal is a bit more CPU intensive, so if you have time later to quickly check that then go for it, but equally if you can't be bothered I'm sure it'll be absolutely fine as is. Those are roughly the stock cooler gaming temps I got.
It is only a little about the effort, i'm just not convinced using the MX-3 will improve anything and cleaning it off carefully takes time lol. And my arctic remover stuff is running very low lol!
If I 'knew' I'd get a few degress less then that would be fine, but I dont, and the temps aren't great but they are kinda what I expect from a stock cooler. Air flow in the case isn't great either and there are few ways to improve that, though I could switch the psu over so it pulls air from underneath rather than the pc cavity.
All this is time, and with a PhD, a 3,5 year old and a 1.5 year old, time is at a real premium!