On the MK ditto:
The neutral position can be played any way that you like, if you're good enough. If you read him, and space well, you can counter anything he does at almost any time. Being in the air isn't bad, although knowing the timings for everything and how to bait from the air is a lot more difficult than playing grounded, so if you're learning, playing on the ground can be better.
Fair can be good for spacing, also.
Learn everything you can bait, and practice punishing those things. Find which positions you can punish whiffs in, and gravitate towards those positions, and don't whiff yourself, 'cause he'll be doing the same lol.
Here's a really big tip for being offstage:
Get lower.
Recovering with dimensional cape is really good if you space it so that you can be uairing safely offstage, preventing him from attacking you while covering the ledge (but not so close that he can hit you), but close enough that if he were to grab the ledge and you DC, you'll go past him and land on the stage (he'll get a free fair, but 10% for being back on stage isn't so bad).
If he's charging Fsmash, know that your glide attack can beat it if you tilt up and tipper it. It's really helpful if you're playing someone who likes Fsmash on the ledge a lot, if you don't use glide attack it can be a really tough option to beat.
If you're below the ledge, practice from how low you can be and still be within range of using a single double jump, and then a shuttle loop, and getting back onto the ledge or stage. If you know that spacing really well, any time you're being edge guarded and you're afraid of DCing, you can just get lower than the MK, and if he commits to an invincinair or something, you can punish it afterwards with a free uair or shuttle loop.
Don't overcommit your juggles, MK comes down eventually. Although don't be afraid to throw out a uair, either. Just be careful with your chasing, as a jump>uair is more susceptible to getting falling-dair'd than a falling uair is. Or even to getting beaten by a falling air dodge.
And DON'T just throw out random shuttle loops in the air. I mean do it if you really feel it'll hit, but be weary of it. Although at the same time, learn which things it can punish, because it does have a LOT of uses, and you wouldn't want to restrict yourself.
Pretty much all of MK's aerials can be punished on shield with grounded shuttle loop, although the rare perfectly spaced fair can avoid it, and I think crossup-fullhop nair can beat it, too.
Although if it can be punished with dair out of shield, use that instead (as with most matchups, but not all). If you get to 110%+ with shuttle loop still fresh, that's a big deal.
If you're standing at the ledge, and they're offstage, and you shield their uair, and they used a double jump, you can up B it EVERY time. If they do a falling one, though, you can't, and if you throw out a shuttle loop that'll miss, they have a better chance of recovering.
You can juggle him with uair, but don't just throw out uairs. MK's dair is comparable range, so if he times it well, you still have to mix up your timing.
If he tornados your shield, and he lands near you, you can Dsmash and it won't matter if crossed you up or not. If he landed far away, dash attack is pretty good because it lasts a while, and your timing won't be especially important, but often you can punish with a dash grab.
If you're recovering, and he's sitting low as if he's gonna shuttle loop you or something, if you can get sufficiently higher than him, you can tornado straight to midstage. Although it's dangerous because if he knows where you're going, and is good at the spacing, he can shuttle loop your nado, and if you're holding towards midstage, your DI'll be ****. You can do it to him, though, too.
In general, though, the DC to the ledge diagonally is really good.
Above all, though, have fun. It's a fast matchup, and if you're having fun with it, you'll learn it better. It really mostly comes down to good fundamentals, but this is also a matchup that improves your fundamentals a ton, as well. It's good practice, and is very fun. The better player will usually win this one, simply because it's so fundamentals based. Ground spacing with tilts and stuff is great, and you can punish a lot with them.
Is bair first 2 hits -> turnaround grab a legit combo or is it a bit too slow?
Yeah, atleast as far as I can tell. I've never had it miss, but maybe someone like Marth or G&W can avoid with their up B.
Single hit bair is, anyways, I don't usually use get 2 hits of bair so I'm not certain about that one haha.
Dair>fair or bair is a truecombo, btw, and from a shorthop you can fit dair+1 or 2 hits of fair, or 1 hit of bair. So at certain percentages, you can dair>fair/bair>followups.
In general, I think there's a lot of potential in, when aircamping, baiting, and punishing some things that you see with first hit bair, or fair.
