meh, link being broken in brawl would take away some of the fun I find in playing him. I'd still play him mind you, it is LINK after all.
As to the vids: For the skills area you guys are at, I guess you're rather well off at present never stop getting better though.
Ash needs to get a few obvious things down. First off Ash: You need to learn the value of the shine. Fox's shine is one of his most effective killers. I saw you shine spike once in the second match, do more of that. Also, fox's shine is good for starting comboes and keeping people away.
Second: Fox's smashes are actually quite useful. I saw you smash a few times out of what looked like desperation. Don't be afraid to smash every now and thenm. His Usmash is especially deadly, except on DRL64.
Third: Your movement in general needs some work. More wavedashing all over the place is generally good for a Fox, dash dancing doesn't usually hurt a Fox's game. For some general examples on what I'm talking about check outthe fox's in this thread
I'm not exctly a Fox pro or expert but I play with these guys almost every weekend and they're actually quite good. Zen has actually played pretty much the best Fox in Canada and stacked up fairly decently; in a tourney no less.
As to the Link, I have no specific vids to show you, though the ones NJ'z put up are good. Your movements could use a little work though. Way too much rolling was the most obvious problem.
Also, you really need to learn the value of the up+b. One of Link's most valuable moves. It can kill decently early and not just as the spin spike.
For the most part, everyone here has given some decent advice, follow it and you should improve.
Edit: The link to the thread I posted doesn't appear to be working right now so if you want to find the thrwad, go to the 1v1 vids section and look for a thread called Deox (Peach)vs.Uber Mage(Fox/Marth). It should be on the third page or so.
Edit#2: Wow, I'm stupid, I didn't even notice the next page of the thread. as to those matches though, it's hard to give a proper evaluation because your opponent didn't really seem to know what he was doing. His Shiek definitely needs to be more aggresive. A passive Shiek is going to be pwned senseless by a Link that is anywhere around it's skill level.