You'll probably encounter better Pokemon the higher level you are, and i'd say both moving/stationary might just get you the same yield. I've gotten plenty while sitting in one place.
4K is definitely better than 1080p, especially in pixel density. I do worry if we'll get the point where resolutions are so high we can't even tell, but 4K is a definite improvement, if just for visual clarity.
Appraisal's useful in a way, gives you some general ideas about the Pokemon. Especially when it comes to Stats, which is good for gym battles, I guess.