In Soul Callibur 2 Link's boomerang and bombs are there just for show. They have close to no purpose in an actual battle whatsoever. That's actually a weakness because those moves replace what the other characters have as special moves. The bow does have a few uses in combos and such, I think, but still isn't that great.
In SSBM, Link mostly depends on his projectiles. He's generally too slow and can't combo very well. Mostly it boils down to using the projectiles to damage, then finish off with the double sword smash or the sword plant. His down-tilt spike and up-B work wonders as well. But he's just too slow to compare against the "upper" tiers of Sheik and Marth. Young Link has speed, but not enough finishing moves.
That said, I really hate the tier system in SSBM. I know it exists, but I simply hate it. The more I play, the more it feels like Marth and Sheik are superior to Game&Watch and Kirby. The tier wars that used to happen around GameFAQs are even worse (do they still go on? I haven't checked that board for a while), about the same level as the Creationism v. Evolution debates around here.