Is it allowed to refresh chunks by pressing F3 + A since you may see entities and particles through walls if you do this? Also is it ok to spam it to see better?

Interesting and innovative strat idea, but I'm gonna guess this wouldn't be allowed; it'd be kinda like unofficially using using x-ray.

I may be wrong but I think reloading a chunk also reloads all the entities, particles, and almost everything in that chunk so I don't think I would help you see anything in the first place.

Try it, I use it in survival all the time to find lava and caves easier. You can definitely see entities and particles while the chunks are reloading.