I've stayed out of this thread mostly because there wasn't a whole lot of information to go off of. But now that we have the boyfriend here, maybe we can address each issue individually. Namely how lsysdev and the boyfriend can properly train their cat.
Here is a site on how to train your cat to stay off of counters and tables:
http://www.petcaretips.net/cat_on_counter.html. This is a good one to teach him because you're right; a cat shouldn't be on a surface where you eat or prepare your food.
I'm not sure how to train a cat to stay out of a certain room. It's something I've not done or seen anyone have much success with. I did find a .pdf file online that addresses having cats and a new baby. Here's what they said:
"Congrats on the new addition to your family. And good for you for not following the too-common advice to find new homes for your pets when you became pregnant. Too many pets become homeless on the recommendations of well-meaning but misinformed friends, parents, and physicians.
"The good news is that cats and children will co-exist happily, but getting to that point does require a modicum of common sense on your part. Cats don't smother babies, despite old wives' tales to the contrary, but its still essential to keep your pets and your infant child apart unless you're supervising.
"You cannot really train a cat to stay out of the crib, so its better to put up a barrier to keep your pets out if you're not watching. A common bit of advice is to replace the nursery door with a screen door. It's not hard to do, and will allow you to hear your baby while keeping the cats away from the crib.
"Cats sometimes forget their house manners at times of household stress or change. If your cats start forgetting where the litter box is once the baby arrives, don't punish them. Stressing them further will only make the situation worse. Instead, ease them into new routines by keeping them in a room away from all the hubbub for a couple of weeks -- a spare bedroom is ideal. Be sure to provide them with clean litter boxes, food, water, and a scratching post or cat tree, and don't forget to carve some time out of your new routine to reassure them with praise, petting and play.
"Pets are good for children! If you gently introduce your pets to the idea of having a new "sibling," your child will be well-positioned to learn the lessons of responsibility and compassion that pets are so good at teaching."
So there are some solutions for you. Like my fellow board members, I would like to stress how important it is to not punish your cat. Generally punishments like hitting will only lead to more behavioral problems.
Good luck with the pet and the baby!