Can someone confirm what N-Spec is good for? From experience against Tails I'm assuming it's for zoning when used on the ground and stopping rushdowns/approaches when used in the air.

Edge guarding. ie If Fox is below the stage, Tails can cover diagonal up-b perfectly with this -> free dair

It's good for surprise short latitude aerial charges, and for comboing into another air attack. One of my most common attacks is standing photon cannon to bair. No one else does this but me as far as I've seen.

its also used for edgaurding as others have said. it also can be used as a combo maker even if they fall out of hitstun, if they have no jumps left it can force them to dodge or get hit and immediately killed with a fair , and if they dodge they will most likely not have the recovery to survive. it also destroys all projectiles that are not crash bomber or Samus' neutral b. it can also be used to stall for time when trying to recover, and can be used to make a high recovery somewhat safe.

Just started trying out Tails a little. Fun character, but I gotta say his spike is a little too free imo, at least in the ways you can set it up. He has two moves that can be spammed to maneuver someone to the ledge relatively far from it, and the dair itself comes out super fast and has a decent hitbox. Fast fallers are especially helpless. Just seems a little easy as far as spikes go.

9a was nightmarishly strong. Beginning of 9b was reality. This patch Idk what to say about it being too strong or not too strong or w/e. I miss when it bounced, but thinking about it I can see why bounce effect would be a terrible idea.

it depends on the opponent, if they DI upwards on the setups they can usually recover too high for the dair to be a safe option, but vs fastfallers its pretty "free".
if your charecter can defend themselves off stage, such as ZSS or Samus, it gets hard to dair. tails also struggles vs opponents who can stand their ground. understanding the DI game vs tails is a massive component in beating tails.

Could you tell me which characters can stand their ground?

projectile characters, characters with great out of shield options, characters with decent disjoints. fast grabs are very key, captain falcon cannot punish side-b on shield safely due to his grab taking slightly too long to occur. (or this is what multiple tests with another player have lead me to believe).

characters with high priority approach options can also hold their ground decently.

I have data to support that Falcon's grab speed is average, actually (at least the same speed as Fox's). I hypothesize that all characters grabs come out at the same speed, with the possible exception to tether grabs.

This is correct.

Bomono used to swear up and down that the kirby tails matchup was 60-40

The patch probably just made that true.

tails vs tails is a 90-10 matchup.

Definetly. Anyways, does anyone have tips for the Puff MU? It feels like just her airials stop Tails whole moveset. Nair even can beat Spindash if Im right. And since Tails is no campy character, my approaches just help Puff more than me :-/

Neutral special and neutral air are your best best, tails nair is very hard to beat and even if it beats it neutral spec will always beat a attack, just learn to use that to your advantage.