Performance-wise, all those games should be fine. Haven't tested V Rising on integrated (on my 6850+680m), but the other 2 are great. NMS with FSR2 will probably allow you to go native res after upscaling.
Battery life will depend on your settings. Make sure you use vsync or a frame limiter in every single game.
I don't have my AMD FW yet, but I'd expect about 2 hours based on specs and expected power draw, which you may stretch to more if you tune your games and power settings.
Surely someone will come in who can attest to their experiences
Do you tune anything to reach that longevity? That's impressive