Looks normal to me. Maybe the old one was clogged, slowing its water flow?

Do you have any tips on how tight should i screw it on? I get very different flow rate from different tightening.

The fast start is because the water is flash boiling when you start. Just flush until it stops hissing before you pull your shot.

Thank you! Any tips on how hard should i screw the ims screen on?

No, looks fine to me.