Help with Hop-up and scope?

I can't seem to zero in my scope perfectly. On my 50mm I ran out of clicks to go down, so I borrowed my friend's scope, and the same thing happened with his(different brand and size). I'm kind of a scrub, and I'm not completely sure about how the MOA works, and zeroing my scope.

I have an Well MB08
-PDI Hop-Up
-Firefly Hard Bucking
-Prommy 650mm 6.03
-Laylax Cylinder head.
-Laylax Z-trigger
-Stock: Piston, cylinder, spring, spring guide.
-3-9x30mm scope 1/4 MOA
-1-5 MPH winds

I haven't really adjusted the PDI too well, and I don't want to fuck with it too much since I stripped the old set screws, and the stock cylinder head was severely scratched up because they were too far down, and out of the holes when I wanted to try lowering the hop-up.

Alright at 54 FT(~18yards.) I can hit a 6in by 9in target 10/10 times with about 3-4 inches between the farthest spread Using a 8-9x zoom. I think that kind of sucks. And It's always about 1-2 Mil dots higher than where I aim, and 0-1 mil dots to the right. No matter how much I adjust it. The up/down is as far down as possible.

What is the MOA for 4 inch spread at 54ft?

I also was shooting at a stop sign 162ft(54yards) away, and I hit 5/10 but I was aiming about 6-8 mil dots right, and 3-4 mil dots down, in order to hit it. After about 100 ft(~34 yards) the BB would fly sky high, and curve like hell to the left. Hence me aiming so far off the target to hit the stop sign. This was using a 7-8x zoom. 1-3 mph winds

What can I do about this?