LOL

i love you, +rep'd

Pantheon isn't a carry : he refers to support pantheon

Pantheon isn't a carry (though it'd be hilarious to build attack speed on him for fast block procs), I'd imagine you need someone on your team who can DPS, else you'll have problems against very tanky comps.

If your definition is like that...

I don't know. Zed, Kha'Zix, Xin Zhao, Poppy, Pantheon, Garen (with full AD), Renekton (with full AD), Irelia, Blitzcrank (He has AD scaling with Power Fist), Vi, Darius, Hecarim, Lee Sin, Nocturne, Olaf (with full AD), Rengar, Riven, Sion, Talon, Trundle, Udyr (with full AD), Volibear (with full AD), Warwick, Wukong, and Yorick can be ADC, right?

If they just go bot lane, will they be ADC?

Or rather, you probably meant that AD Carry is "Someone who carries with AD".

Then do NOT go bottom lane with Yi. Go play him at jungle, and make him more effective. Zed carries game with AD. He goes mid. Vi can carry games. She goes jungle. Irelia can carry games. She goes top. You get my idea.

Yi is weak early game, but his ganking power is strong, clearing camp is easy, and he has sustain. Go jungle, and he will still be *ADC* that you talked about.

If he goes bot, he will be wrecked by autoattacks, Rocket Grab, Crescendo, Infuse, Glitterlance, Hymn of Valor, Help, Pix!, Piltover Peacemaker, Buckshot, and other harass and CC.

He cannot ADC in the bot lane, but he can ADC in the jungle.

1. Yi is not a tank, to make it one is just to waste his enormous scaling potential with AD
2. As for teamfights, I'm actually writting the gameplay guide so stop needlessly pointing at them
3. This build is no joke (well the 5 Bloodthirster one is)

Nope, easily interrupted by most supports CC

Use moar clarity on tank yi
-1 not labeled as "humor" ;)

Arguably, you could say that his meditate is his survival tool, but the cooldown is just way too long to be a viable one.

Lagger is right, generally speaking. A ranged AD is necessary for getting towers, zoning and positioning properly. This is why melee carries are so unpopular. Fiora and Tryndamere have records of being used in the bot lane, even at high elo but that's because they have an actual survival mechanism. Yi does not, however.

Personally, I've had a lot of success in S2 with bot lane pantheon. Not sure if it's still good in S3.

Well, I'm actually pleased to know the idea behindmy guide is playable on low elo ranges (It's something!). And you actually point some of the most important weaknesses of Master Yi. But you are making some important mistakes, and it's the ones about his gameplay. What I feel about the new Yi is he lanes on bot lane far better than on top lane (by personal experience and at least with this guide). So... why? With this guide you actually need a good support ( Lulu and Nami are my best friends) or a tank (a Pantheon on bot lane taking all the damage coming my way was just so epic). Until you get the bloodthirster Yi is extremely support dependent as an ADC, and will generaly doo quite poorly if not supported well or not supported at all this particular way of playing yi will most of times fail because of one important point:
This guides heaviy depends on rushing a Bloodthirster, getting a B. F. Sword on your first back is just mandatory as you want damage above all and already have life steal. This is impossible to do if you receive all the harass AND have no one to heal you or act as a shield. A lane with an ADC yi played as I do is indeed a weird lane, as you will most of time start aparently "losing" your lane and when you and your support get your ult it can quickly turn to a double (or triple if their jungler is somewhere near) quite quicly. I m right now trying to write the basis of how to play him.
As for your example of the Caitlyn, I must say that as a Caitlyn player myself, I perform particularly well against her. That beeing sayd, people underestimate yi's capacity to get up close. A cait will harass you to death, but for that she will be moving towards YOU. That's the point where a good Blitz, thresh, Lux or the likes will get her and the rest is history because of your ridiculously high damage output. If your support is a more defensive one, a quick heal/shield can be awesome for those risky actions.
My last points are the teamfights, this is where it gets tricky, as yi is as quickly to die as to do pentas. On this point I am still unsure of what to write, and it's a painfull trial and error system to get when you need to yolo, how to yolo eficiently, and who to yolo (surprisingly it is not always the ADC, or the 3hp guy, in fact most of times I wouldn't recommend starting by the 3p guy as you will be accused of ks even if he would escape and you have great chances of getting him anyway as you have an enormous chasing potential.
Still, thanks for the critism, and I'm rushing the gameplay parts of the guide (which are, I think, the most difficult ones).
Good luck!

No, he does not. To be an AD carry just means the champ will be "carrying" his team by dealing most of the damage throught autoattacks or AD scaling skills (I'm not really sure of that last one thought).

-1. An AD carry must be ranged. This is compulsory.

I play sometimes with a bunch of friends and we try silly stuff when we all play together, but I've always noticed that a melee AD carry may be able to win the lane early (notably Gangplank), he becomes useless late game because unlike any ranged ADC he has no zoning power, needs to be up close to deal damage, and has extreme CC vulnerability.