Lajin, what would you do to Melee Young Link to make him a more viable character? Try to consider things which would specifically help his worst matchups.
I think the killing power of the B+ Fair and combo ability of the B+ Bair, and kill power of B+ U-smash are helpful (although I understand your points about u-smash and we're talking about it in the PMBR), and the Zair helps his range a bit. However, what do you think? Would those tools be enough vs. Sheik / Fox / Falcon? Would you do anything else in addition, or differently?
I'm talking strictly about melee here:
There are plenty problems that YL has with the top tier match ups(and a couple of others), but the absolute biggest problem in my opinion and experience is this:
Those characters are able to move and act quicker than YL can ever dream of doing. Lets take Fox for example, that guy can literally run circles around YL and not give him any time to breath. All of your close range moves do not either come out fast enough to stop Fox's oncoming onslaught or your moves simply do not have enough priority to also stop his onslaught. YL's worst match ups are against characters that are a lot faster than him.
His second biggest problem is inability to kill fast enough. Sure he can rack damage pretty well and camp, but he has trouble killing and finishing off his opponents while all the top tier characters have absolutely no issues with this. His main offensive for finishing opponents off are to hit them with a projectile(safest approach) and combo them into a kill move(u-air, n-air, d-air depending on the character). Problem with this is the character always has to be a pretty high %s to guarantee the kill while Fox/Sheik/Falcon have absolutely no problems with finishing their opponents off and can do with ease(Fox has a ton of kills moves + set ups. Sheik can simply f-tilt or d-throw to f-air or whatever she wants to do. Falcon can has a million setups -> knee).
Of course there are other problems, but these are his main issues. If these two problems can be fixed/overcome, Young Link would be a lot better. I'm currently working and thinking up new ways to overcome this problem(in melee), but obviously its not easy cause if it was he wouldn't be low tier in every tier list ever made. haha.