LAWL skimmed the OP. I didn't realize you changed it.
I think Falco with Fox's shine would be really good because one of his biggest issues is setting up a KO move at the end of his combos. His combo tree changes, but in a lot of respects I think it actually improves. Shine > d-smash / f-smash on Sheik & co. seems pretty cruel. SHFFL Dair > Shine > SHFFL Dair > Shine > SHFFL Dair > Shine > Shine > smash attack of choice also seems kind of cruel on anyone he can waveshine combo. You can even continue the combo with up tilt if you want, which is kind of bonkers. I guess his pressure gets a bit worse because of his slow jump but... I think people would just shine-grab and retreat aerial even more than they currently are to counter that, or just camp more.
I dunno. Call me crazy, but in a lot of respects this Falco actually seems slightly better to me than the current one against a lot of characters. Having an automatic 40% flatland combo that transitions into an air-combo is pretty bonkers. His game vs Fox gets worse, though. But against everyone but Fox (and maybe Puff to a small extent) I think he actually improves LOL.
edit: The more I think about that kind of Falco and all the little positional traps he would have, the more disturbingly good it sounds. Waveshine the opponent so they're close to the edge and then dairing them would be such a stupid trap for killing Marth and several other characters. I'm gonna stop editing this here but like... wow that's stupid good. So many doors open for him...
Okay, so yeah. Since I think Falco with Fox's shine might actually be better than current Falco and Falco with MCable dair is obviously worse than current Falco my opinion is pretty obvious LOL.
Laser thing is here:
Lasers by far. The other two don't even affect him that much as a character because they just alter his punishment game. All his fundamentals remain the same, the only difference is that his combo execution becomes different, and his edgeguard algorithms change slightly.
That said, for his combos alone a Falco without stunning lasers would not drop below top of mid tier. I'm pretty sure that Falco is still better than like Ganon. Falco's not actually THAT slow, it's just his speedy movement is awkward; his walk is significantly faster than his run and he therefore needs to WD to build momentum first to get moving. This is a pretty big handicap, but more because it telegraphs his movement than actual speed issues IMO.
His defense without stun lasers is still pretty decent. CC shine, CC d-smash, shine oos, etc. would still be amazing against low-range aerial approaches and stuff. He's also got his retreat AC bair. It's not as good as it used to be, but it's still a pretty good mixup. He would still be able to shoot them from a distance to force people to leave certain zones too, just not as well as before (and he couldn't approach if the opponent remained in the zone, which would make for pretty big playstyle differences).
His combos largely wouldn't change except his tech chase on the stage's ground level would be worse because in situations where roll away can't be followed directly, he wouldn't be able to shoot lasers to force them to auto-shield.