Perfect and light shielding should definitely be back. And teching, and dash dancing, L-Canceling (or **** it, make it automatic), Melee's tether mechanics, Melee's ledges and especially hitstun. Those are things I can at least agree with 100%.
I agree with most of this, although instead of dash dancing, the running startup speed should just be a lot faster, as should the run restart time (with none of that slowing down running crap; that has been in Smash since what? Melee? I've always hated that). Also, teching never went away in Brawl, although it was way too slow. If anything, teching should be faster than it was in Melee, not slower.
And yeah, Melee's ledge mechanics (albeit with a bit of that Brawl "jump," the two sided recovery, and universal better recovery than Melee, especially for weaker/heavier characters) would be very nice. Oh, and Melee's hitstun isn't particularly needed, but something that similar sets up sexy and fun combos, tech chases, kills, and situations are things that we should definitely have again, along with spiking causing gimps (which it looks like it can).