Normal temps & cooling

Recently purchased a XFX R9 390. Has been working great so far but had some questions about temperatures.

I'm not overclocking it at all(yet) and idles temps sit around 30C with 35-40 when watching movies or something. When gaming(Witcher 3 max settings) the temps top out at about 70-72C. I've looked around and found conflicting advice on whether or not those are safe temps to be at.

Secondly, I'm wondering about aftermarket GPU cooling. I've always used stock as I've never had the need to do anything aftermarket cooling with previous cards. Are GPU coolers difficult to install? I'm not someone who has a ton of money lying around and screwing anything up would put me out of a PC.

Thanks in advance for any advice.

The Temperatures look fine, 95°c is the max for 290/390.
I don't personally think aftermarket GPU cooling is worth it unless its a watterblock for a custom loop.

Perfectly normal and won't cause undue stress on the card as they're made with those temps in mind. You could fit an AIO water cooler if want to run the card in the 40s. They tend to be fiddly to fit but not actually difficult following the instructions.

30°C is normal idle, <80°C is normal for load.
You are good.