Just have to feel it out as it depends on the team.

If they're hard pushing a lot, the team should be rotating as soon as a teammate hears a footstep. If they're attacking a particular site often, maybe have a sentinel defend there, or prepare to smoke it to delay the push. If you're getting picked a lot, just fall back and play for retake. If not, mix up your plays so you're not predictable. Don't stay in the same spot all the time.

Slow push is quite annoying because they will waste all of your team's utilities and rotate to another site if they think it's not safe. Don't rotate too quickly as they will most likely rotate. It would be good to have a lurker to catch them rotating or box them into a corner. They may also have a lurker so someone has to be watching the back.

Playing for picks is just a bunch of little deathmatch. You just have to win your fights. If you're getting destroyed and not feeling too confident, don't take 1v1 fights and play with your team.

5 manning a site is simple, and is often done in eco rounds. Just rotate to the other side of the map. If you or your team spot at least 3 people it means they are stacking the site.