I'm no expert on poodles, but:
Any dog can have an underbite. Don't know about it being more common in poodles...
Miniature poodles are definitely "small". They can also live a very long time!
Poodles are extremely intelligent and easy to train.
Generally speaking, most dogs are "pack dogs" as dogs are very sociable animals. That does not guarantee that every dog will like every other dog though!
About the french kissing..ewww!