The most commonly used controller (other than keyboard) is probably the Dualshock 4, but really anything works, it's up to your personal preference.

I also have a surface pro actually and I record at 360p 30fps and have had no problems. You'll be fine.

Unfortunately, LiveSplit does not support timing between multiple chapters like this as it simply reads the in-game time and therefore cannot add time between chapters. There are a few options of how to time this, but my personal favorite is to create a new file, input the cheat code, do both segments, then check the journal for the final time. The downsides are that you don't get checkpoint splits and you have to delete the file and recreate it every time you reset.

There's a pin for that in the Celeste discord. I think everything you need is here: https://docs.google.com/document/d/1OglBKMiR_nDIgPTp5LHldOPj9mLxln4HKw_F5C3XDl8/edit TL;DR it's a script that resets for you, but can only be used on PC version and can do some weird stuff and/or invalidate your runs if you're not careful.

Yes, you can kill the enemies in any way you like. When I did the trial, I used arrows/bomb arrows most of the time.

It's not possible to beat Cascade kingdom only getting moons touching the ground, and only getting moons in the air is dumb and arbitrary and changes very little of the route.

You don't need a timer showing, you don't need a capture card, and you're allowed to go out of the game and do stuff, as long as the video keeps going.

Yeah, the seed thing works by having the clock advance (via daylight savings) after you plant the seed but before you leave the rumble room. 1.3 digital is ~10 seconds faster than 1.3 physical, so in my opinion you don't need the digital version unless you're going for subhour, but if 10 seconds is worth $60 for you, then go for it.

Cool but probably not useful like this since shield clipping is way faster

This would basically be any% but with a slightly different castle route to pick up ancient arrows, and simply hitting ganon with an ancient arrow instead of a light arrow. IMO, not different enough to be its own category.

This should answer all your questions:

Those cutscenes are still there in All Dungeons, I don't see the problem.

Rolling speed loses quite a bit of time. You also can't do spinthrows or upthrows, which loses a bit of time depending on which strats you go for. Not being able to do homing cap throws is big too since you would have to throw really accurately and can't do any dram strats.

That sounds pretty boring to me. While there are some interesting routing options, there's just not much you can do in the actual run. It would basically just be sprinting and whistle sprinting with a small amount of extra stuff. If some people like it, fine, but imo it's a boring category that no one will do.

Probably. Smallant said that the moon dates when you get a moon have to be readable, so you can use that to see if it's good enough quality. Also, audio isn't necessary to have your run accepted.

No, this has been asked multiple times before

In general, anything that uses intended mechanics is not a glitch. So moon skip would not be a glitch because you're just using the game's normal jumping mechanics. The only glitches I can think of for any% are First Moon Skip and all forms of clipping, so a 1.2 any% is glitchless anyway.

I'd watch smallant1's movement guide video for a full explanation, but basically, you can spin the control stick during cutscenes and loadings as well as Mario's actions, usually dives. You can't always buffer a spin, most noatably, you can't do it after a death animation, but also a few other places.

As far as I know, 1.0 and 1.1 are nearly identical. The only tricks that are impossible on 1.2 are first moon skip (~30 secs), sphinx clip (~15 secs), and turnip clip (~10 secs). So 1.2 is less than a minute slower. I feel it's worth mentioning that both scooter clip and moon clip work on 1.2. P.S. My numbers might be wrong, feel free to correct me, but this should be close to correct

EDIT: This is only referring to any%; other categories are different.