It's the shape and dimensions of YOUR face and cheek which matters. No one can tell you based on the rifle, scope, stock and rail. The right scope height will be comfortable with a firm cheek weld with you trigger hand and stock. A proper scope hight will guide you to a fast and repeatable hold with your eye comfortably centered on the scope with correct eye relief...for your face.
Scope height above the bore does change the zeroing and point blank range of a rifle and scope. In my opinion that's less important than having a proper cheek weld. To adjust both you need to adjust both the height of the scope and the height of the comb of the stock relative to the bore. (or select them correctly to start with based on other rifles that you know fit you.
Should you use an adjustable cheek rest? It' s your face and cheek. Go ahead and mount it with what you have then see how it fits. Check how much clearance between the scope and whatever interferes with it (usually the barrel or rail). Then check how you face fits in the positions you'll likely be using it. From that determine what you need to do.