Greetings, community!

I purchased my G750JS 3 days ago and so far it has been an outstanding experience. My previous laptop was a HP which after a few months started reaching a constant 95ºC in both gpu and cpu. So when the time came to upgrade, better cooling was a priority. As I write this post I'm still enjoying the experience and not reaching more than 80ºC while gaming, in the middle of summer in Chile. Yet, I can't help but wonder why is it that the GPU fan spins at arround 5000 RPM, when the ASUS Tweak software clearly allows it to run at 25500 RPM. Now, my question to you (since ASUS support did not provide a satisfying answer) is:

Shouln't it be better for the hardware to have the fan spin at max speed?
Since I do not mind the noise at all, should I just leave it running at full speed while gaming or does this do any damage in the long run?
Also, is it possible to make it spin at a higher speed, say 8000 RPM without any drawbacks using third party software?

Thank you for your time!