*Sees below* Wow, it was your burfday??? Hope you had a blast! =]
Kirby's worst match-up is Ice Climbers (Large disadvantage). As you know, it has to be played as a hit, run, bait, punish and most important, patient match. Kirby can practically get shield grabbed out of practically every move. His other match-up are disadvantages. An uphill battle but certainly not unwinable. Characters that are in this category are G&W, Olimar, Marth, Lucario, Meta Knight, Snake. Other small disadvantaged match-ups are; Lucario, ZSS, Toon Link and Wolf. The rest are even-ish or in our favor with a small or moderate advantage. Overall, Kirby is a pretty balanced character as far as match-ups go. Also, it's the match-up knowledge that counts, too, but you probably know that already.
One tidbit, I'll give you that he can do. I recently found this out myself while in the Kirby boards... Ah-hem but Kirby has a little Boost toss. It's not a glide toss but rather a jump canceled item toss. It's not far but it's moderate. I like it. It's pretty cool. Try it out!