kokii

yes as long as its stable
 

That's great, you can use up to 1.45V as long as temps don't go over 85C.

the highest ive ever got on a 6600k is 4.6

Yes that is fine. I wouldn't use Prime 95 for testing though, as some versions can damage your CPU. Use Aida 64, Asus Realbench or Intel XTU.

Run a stress test for 10-30 minutes every time you bump up the overclock. Once you find your max overclock, I would recommend running a 8-24 hour stress test to insure it's fully stable. You could do it overnight or something. 

The worst thing that can happen is that it overheats. Temps wont get much higher than what you see in a 15 minute stress test. If it crashes it will usually just restart or shutdown and you will either have to increase the voltage or lower the multiplier.

If you have anymore questions, feel free to ask.

Yes thank you very much for the info