Hi, That's a lot of questions in a small bundle. Power should be adequate. If you want to add more fans, you'll need some kind of fan hub and check to see if each header on your board will deliver enough power for additional fans. If not you might want to add a usb 2 fan hub to a spare header on your board.
I presume that you have kept an eye on temperatures with your current fan set up? You need to observe what's happening temperature wise and configure your fans around that.
I have a small case and I have a 280mm Rad on the top with two 140mm fans blowing out the top, two 120's on the floor of the case sucking in, and two 120's on the front sucking in. I have mine configured to run the top two at 500 rpm and the other four at 650 ish, they then all ramp up to custom curves in pairs determined by my zone selection in terms of temperature in different areas of my build. This allows me to stress test, to work out the best configuration which will balance noise with the need to keep the temperatures in a good place.
How will you know when it's overclocked? Either the app you use in windows to overclock or the setting in your Bios you choose will bring that fact to your attention.
The little fan, does it show in any of your data within your monitoring? Read the manual that came with the board and see what wisdom if any it has on the subject.
Or maybe be more specific about the intended location of the fan and its purpose.
Again, overclocking your graphics card will be something that you personally action, you'll see when you have changed a parameter, and if it crashes you'll know that's not the best setting 😉
Regards
P
