1. 100 HP is very nice for a basic. Slightly above average for a non-evolver. Weakness is bad, with Donphan keeping Cinccino and Zoroark in check. Resistance is non-existent, and retreat is bad, but not unredeemable. Since his attack takes a DCE, he can use the same DCE to retreat.
2. The first attack is situational, but potentially game changing. For a mere DCE, 90 damage is very, very good. However, 20 for a DCE is absolutely terrible. Head Charge... should really never be used. four energy on a single Pokemon is gluttinous to the extreme. If you put four energy on a Tyranitar Prime, that's one thing. Those four energy produce 120 damage. In this case, though, it only makes 80 damage, and has a 50/50 chance of knocking down Bouffalant's HP by 20. Not good.
3. No particular combos other than any deck that runs DCE. The obvious choice would seem to be Cinccino, but honestly in that case you're better off just running more Cinccino. Zoroark + Bouffalant + something else is a decent combo, though. Also, running it with Cynthia's Feelings is nice, and gives you a better chance at coming across those DCE.
4. That is the problem - the most logical deck partners are also weak to Fighting. Also, there are two commonly played Fighting types, Donphan and Machamp. Problem is, they have different weaknesses. Running Bouffalant in Psychic or Water decks makes the most sense. Samurott appreciates the backup, for sure.
5. Meh. The front half looks like he's planted still, the back half looks like he's running. Not a good design, honestly. I like the angry face, though.
6. Limited 4/5 - Good REVENGE killer.
Unlimited 1/5 - gimmick is gimmicky. Lots of other cards do better and don't rely on having something die.
Modified 3/5 - A decent tech, but most decks will make short work of it.