Contrary to what some might call it, "popular belief", you WOULD benefit from installing CCC. I do not live in a place that is as hot as yours, but this summer temps in my room reached 33ºC and during a full gaming session my HD 5770 topped at 82ºC. That's not a very high temperature and, to my standards, completely tolerable. You should, instead of messing with your card's BIOS, since you do not know what you are doing at 100% and there is a risk of bricking your card with a bad flash, I strongly advise you to search for another option instead of flashing the BIOS. Like, make sure your case has good airflow and if you still want to get special attention to your card, get a fan for the side panel or in the front of the case to make cool air reach the card. Also, you could replace the thermal paste on the card's cooler.
I'd like to point out that those settings you showed for the fan would not work, in my opinion, unless the fan was an ideal (perfect) fan. Hysteresis can't be that low, nor can the speed up time, because a fan cannot simply go from 0 to 2000 something rpm in less than a second...unless it's specially designed for it. And this is not the case.