@HereIAm I have this exact setup(homeassitant, frigate, image detection using intel igpu) and i run few other containers (jellyfin, nextcloud) with no issues so far since its for home use. Your GPU is powerful enough to handle much much more than this.
And for cameras i would suggest to check the frigate documentation where they've indicated which cameras work best. RTSP is fairly common and i use it for my cameras with no issue.