Paul should have the front sight inserts inn either meta or a set in clear plastic. Or if you are feeling spendy, you could go with an 18mm front iris.
Sounds like you have a rear iris. The little sliding plate with three hole was used to slide to your desired aperture and tighten in place buy tightening the eye cup.
You should be able to free up the bolt slightly by greasing the bolt lugs and the primary extraction point on the bolt handle. I would not worry too much about the safety but it could be rubbing on the stock. I have never been in a situation where you would need a safety on the range (usually bolt open a breech flag inserted)
Your sight are more than likely 1/3 MOA, in other words 3 clicks per minute.Turning the knobs clockwise is up for elevation and right on windage. Easy way to remember this is clockwise moves the sights towards your hand. Once you have zeroed the rifle, move the scale plates to zero for your windage. Your elevation plate may or may not be able to be set to zero, that's ok, just set it to any nominal hash mark, ie your 300 yard zero may be 5 minutes or 10 minutes instead of zero. Hope this helps.