Ok, first of all, this is a lot to ask, but:
I'm running a Nvidia GTX 960M, with 8gb of RAM and a Intel i5-6300HQ, should I use NVENC H.264 or QSV H.264. Yes, my laptop is old, and I play CPU demanding games (eg. Forza Horizon 4), and was wondering for recording which one I should use, and which preset. (x264 is not an option, my computer will probably kill itself). I record at 30fps, downscaled to 720p. As well, what should my bitrate be?