I agree with Abra that there isn't a right answer here. That said, let me give you some food for thought, okay? I know you are working on crazy hormones and likely sleep deprivation, not to montion the insanity of having to life your world around this itty bitty (cute) thing, BUT while you deserve all of the kudos in the world for being the mama and all that that entails, **you aren't the only one here who had a baby**. Your husband became a father for the very first time. That's big for him. And HE is somebody's son (your in laws to be exact), and (especially if he is the first of his siblings to have kids) his parents became grandparents. So many grandparents now are realizing they worked their children's babyhood and childhood away (especially the men), or they just MISS it, and being a grandparent open whole new doors and avenues for them to get to have FUN with the new little ones.
How would you feel if one day down the line your little son grows up and he and his wife has a baby and she tells you that you're only allowed to visit a few times a month? Would that not break your heart?
And so what if he asks tons of questions - see it as it is (not as your irrational hormones are telling you - that he is questioning your abilities as a parent) that he is obviously AMAZED by the wonderment that is your new son, and he is CURIOUS about him. Take it as an opportunity to school him on babies, their functions, the basics, etc, and once he's "got" it - LEAVE THE BABY WITH HIM AND GO TAKE A NAP!!!! Use him for every cent of grandparent worth. He obviously wants to be involved, let him. Who's it going to hurt? Might you just benefit? (My husband would like to add - think about it: The more you can get your baby to bond with grandparents NOW, the more likely it is that babysitting will be easy and natural in the future - like 18months from now, where WE are - and you just might get a date night or two out of it) And if he were to get sick tomorrow and die, would you begrudge him these visits? Would you feel ashamed of yourself for trying to keep him away?
I didn't understand my husband's grandfather who did much the same with my daughter. He just wanted to be there, see her as she grew, and I regret FULLY to this day every time I asked my husband to get him to leave, as he is now dead and I can't take it back.
Now, we've moved away and my in laws have never even met my 15 month old son due to it being "inconvenient" for them to travel here. Trust me, I really wish I had your problem. It breaks my heart that they are so hands off.
So anyway, sorry this is so long. I hope you read all of it. You are not a bad person for feeling the way you do, I did once as well. But, hindsight being 20/20 I see now that it isn't hurting anything, and you can actually benefit a great deal from it. I hope that this has changed the way you view your situation. I wish I had had someone to change MY view about my husband's grandfather when my daughter was little - he just wanted to watch her grow up, and I pushed him away! (I AM ashamed, by the way, every time I think about it now, and I've cried through much of this)
Let us know how this goes!