Unfortunately, you have the Zotac crappy cooler edition, so there's not much you can do, outside of repasting incase of a bad paste.
1. Nvidia GTX 10-series uses GPU Boost 3.0. How it works is that it checks for thermal headroom and power headroom. If there is still headroom for both, it'll overclock itself. This means, on most default setup, it'll keep boosting until it hits around 80C.
2. If your goal is to lower temp and and decrease noise, you should decrease power limit, and apply an "undervolt." Download MSI and start off with the following settings: -15% power limit, +100mhz core. Keep temp at 80C.
3. If your goal is to squeeze more boost, add a +100mhz core.
4. By adding increase core clocks, you're essentially undervolting, allowing it to achieve the same clock with lower voltage. Power limits and thermal limits take care of the rest.
5. If your goal is to run your GPU cooler, apply temp limit of 75C, +100mhz core.
Those are just baseline settings, every chip is a lil' different. Regardless, understand that unless you change the temp limit, the GPU will keep boosting itself until it hits power limit.
For cooler replacement, if you can get your hands on an EVGA version cooler, that would be the best. You should look for 1060 SC versions.
Regardless, you don't have to worry about life span. GPUs are very hardy, and as long as it's thermally limiting properly at 80C, it'll last just fine.