Yeah, so this is an easy fix, no worries. All you need is the allen key that should have come in the main box with your scope. First, do a little counting. Run the turret all the way to one side, then count your clicks back to the middle. If I understand you correctly, your turret shouldn't be at zero, right? Now you can fix it. Loosen the three screws that are on the turret, without turning the turret. That will "slip" the turret, allowing it to spin freely. Set it to 0, and re-tighten the screws on the turret. Now you should have 65 clicks both directions. If for some reason you don't, then slip your turret again and see if it spins freely or if you feel some sort of blockage underneath the turret; that's the only thing I can think of if you correctly count to the middle of your travel and can still only turn it partway in the one direction. The instructions on how to slip your turrets should be on the last page of the little Owner's Manual that came with your scope, too, on the page titled Arken Zero Stop & Turret Alignment

x24, x28, or some other objective measurement, can you say? I find 8x and 10x LPVOs with a 24mm objective to have substantial image darkening at the top end of magnification, and it's one of the reasons I've got multiple 1-8 and 1-10x28s - the extra objective area makes for a much brighter image at maximum magnification. The larger eyebox is a nice touch as well.

So if you want to stay under $2k and have spent $1k on the rifle, that leaves you about $750 for the scope, right? Figure $75 for a scope mount and then $150 to get a few magazines and a basic bipod. In that case, what you want is a Meopta Optika6 3-18. Go check out this review comparing it to a Vortex PST II 3-15: https://www.youtube.com/watch?v=jKUkfWlUDPM Or, if you'd like to try Arken and aren't in a rush, then get settled in for a bit of a wait and grab one of the next set of EP4s that come up for sale. They're quite nice, and a definite step up from the SH4.

Don't like FFP, and are used to Gucci gear? No, you won't be happy with Arken. They're not trying to compete with the top tier stuff. For a budget around $1500 if you want to branch out and try new brands, get a Vortex Golden Eagle. Sounds like more your speed - SFP, finer adjustments, reticle designed for dialing in your shots.

There's a lot to learn about MOA and Mil. You might find watching a few videos on the topic more helpful than a forum reply, but here's the short & sweet version: 1 MOA is 1/60th of a degree, and it turns out that that amount of angular measurement is really close to 1" at 100 yards distance. So making a 1MOA adjustment at 100 yards moves your point of impact just about exactly one inch; making a 1MOA adjustment at 300 yards adjusts your point of impact just about exactly three inches. MOA is a very good system of measurement if you naturally think in inches / feet / yards. One milliradian is one thousandth of a radian. What's a radian? It's an angular measurement, and there are 2*pi radians in a complete circle. One mil by definition subtends ("draws", basically) an arc of 10 centimeters at a distance of 100 meters. That's exact; no rounding at all. So a 1 mil adjustment at 100 meters moves your point of impact exactly 10 cm; at 300 meters that same 1 mil adjustment would move your point of impact 30 cm. Mil is a very good system of measurement if you naturally think in meters. They are neither of them better than the other, inherently. They are just ways to measure tiny changes in where something is pointing. Whichever sounds better to you is the one you should probably learn on, but eventually you'll probably use both.