Okay, time to answer some topics!
When you first saw Buizel did you think he was the opposite of Mudkip?
You know, I didn't even think about that. But when I saw this question, I was like huh? And then I thought about their color swap and understood what you meant. Interesting thought.
Do you also use your Swampert in contests?
Hmmm... I can't remember, but I think I did. I like my starter to have lots of ribbons on it, so it looks better.
Shiny Swamps or Normal Swamps?
Normal for me.
If you don't start with Mudkip, which water pokemon do you use in your party?
Hmmm... I don't remember too well about this topic either, but I recall training a Pelipper once and maybe half-training a Milotic. I do have one Swampert traded over, I think. EDIT: Now, I remember! I trained Sharpedo! And later, a Walrein.
Which attack does Swampert like to use the most?
Muddy Water sounds good. As Skii said, it combines both types.