What to do as a grad student about an adverse grader?
Of course, you are perfectly entitled to get graded fairly. Talk to the prof, and when you do, concentrate on the factually wrong grades if they are the substantial part of your complaint, because that's where you can provably address the factual incorrectness of the marking. Make absolutely sure this is really the case; if you get that wrong, people won't listen to you on the other things. 

If the professor looks at that, you could add as an afterthought that you generally feel that the grader is overmeticulous, and whether you are really supposed to submit at that level of detail? 

Generally, much will depend upon how well you do on other courses. 

I would completely put aside the thought whether the grader has it in for you, as you have no way to prove it, unless you have hard evidence for that (e.g. some proof of a conflict of interest or something else). I would avoid going down that route, though.