9bar Oh dear should be at least 10bar, 12bar if it's a fresh build.
You have some heavy ring/bore where if that was an accurate test.
All plugs out, engine warm (15mins running), accelerator pedal to the floor, 10 sec cranking, take reading, move on to next cylinder.

TBH with your top end rattle as well i'd just do a full rebuild if you have the money and time mate.
Seems like you have Cam/Lifter problems, Worn Bores/Rings, bottom end is bound to be next