80°C and more is quiet hot for the 560ti and while its within the specifications it wont actually extent your cards lifetime. The downside of non-exhaust cooling solutions is they're heating up your case much more than reference design cards. You really rely on a good airflow in your case else hot air might get stuck and pulled over and over again by the card's fans.
Is this yours?
http://www.caseking.de/shop/catalog/...=17158&imgID=2
As for redoing TIM, it helps sometimes but don't expect a miracle. 2-3°C if anything at all. Be careful with Arctic Silver 5 on GPU's as it is conductive and it also has an extremely long cure time. The best compound for graphic cards is IC Diamond.
9 and 10 are 2x and 4x SSAA (Super-Sampling). No current hardware can handle that well in XIV.
I've 2 heavily overclocked 580's and it is barely playable at 10, 9 works if you just run around and don't get close to any foliage.