I got Barbas and decided to keep him for now but He is a nightmare because he pushes you constantly and often gets in the way of you or other characters you need to follow.

Is there an AI mod to make him act like other dogs that you can buy?

Yes:

http://skyrim.nexusmods.com/downloads/file.php?id=2686

Those damn dogs never shut up. I got a neighbor that has a d...I better not say.

His is the only quest where I break my no fast travel rule as he is so annoying.

I find that all followers like to push my Dragonborn, and get in the way of his melee attacks. Thus, he prefers to travel alone and hates the quests where melee followers are mandatory.

barbas is awesome ino except when he starts fighting some one when hes really far ahead of me and i didn't know he started fighting any one so i just kept running down the path cause i thought he got really far ahead of me. other than that tho hes awesome. cause the first time i played and i came across him and he started talking i compleatly forgot about barbas and vile. and was like wtf and then he started talking about vile and i got excited i think he was one of my first deadric quests maybe 2nd not sure it was back in NOV.

Fixed that for ya...

Thanks for that. I installed it and now he's a reasonably good dog. He still pushes occasionally, usually when I'm talking to someone but that's not so bad.

I just wish there were commands for him like "wait here" when you want to sneak in to a house or something. Make him wait outside. I almost finished the quest for him so I can't talk to him now, he just gives me the last line of the quest every time. If anyone knows of a forced set of commands for him that can be used at this point, I'd be grateful. There are times when I don't want him attacking people, specifically for thieves guild side quests.

If there isn't a command set for him, something like:
Be Passive: Makes him follow but he won't attack anyone, even if they turn agressive.
Be aggressive: Toggles Passive mode off again.
Wait Here: Makes him wait where he is until you tell him to follow again.
Follow Me: Toggles off the Wait Here.

I am not a modder but if someone else can do this for Barbas, it would be great. I'm sure a lot of players would download it.

From what I've observed, Barbas doesn't simply push Dragonborn in a random direction. Barbas pushes Dragonborn to Vile's quest location direction, and does it more than any other follower. This is, I assume, because Barbas isn't intended as a follower and his pushing is intended to discourage the player from keeping Barbas around. Barbas wants to be reunited with Vile, and he wants it badly and yesterday.

It's his AI Package. He's set up to be 100 units from the Player which is just too close for comfort. Other dogs do it too and it's definitely a bug as http://i.imgur.com/70f3g.jpg can happen with the Player and Barbas too.

"My hair is a dog. Your argument is invalid."