Just popping in to give my two pennies on customs, because it really surprises me my particular argument has not been brought up before. To quote myself from a different thread:
This entire discussion is rather silly. Lets use the Sheik example- if Sheik had default bouncing fish, needles, and vanish as customs instead, we would ban them because they make her the best character in the game.
If airbender DK were default, he would be treated like any other annoying-*** top tier. People would complain, but they would adapt and learn the MU. Frankly, I think it all stems from the way customs are presented: like something special and different that you have to put extra effort into getting, as well as being presented alongside equipment. If customs for the entire cast were treated like Mii moves, we wouldn't be having this discussion.
Basically.... Custom moves are totally arbitrary.
There are way too many incorrect things in your post. First of all you make so many assumptions and "what ifs", which really doesn't help with your argument at all.
Second of all, you assume we would ban customs because if Sheik's current default moves were customs she'd be the best in the game... I mean that's a huge what if and basically a useless example that, as I said, doesn't help your argument at all.
Same goes to Kong Cyclone being a default.
Basically what you said was "if current default moves were customs we'd ban them, and if custom moves were default we'd just be annoyed and deal with it" but that's not the case and that's not a reason we should allow customs /at all/, it's a very poor argument.
Also about customs. It's a slippery slope when we ban a handful. Why ban a couple custom moves when we can ban others as well? Also, it's not just a few customs that are broken. The few customs that everyone's complaining about are /obviously/ broken but then there are those who aren't so obvious, and that create game scenarios that normally wouldn't be there and give an advantage to players when they otherwise shouldn't have them in a no customs environment. I mean I don't have to say anything; when a character goes from completely unviable in tournament to extremely viable (DK, Palutena), you know something is wrong.
Then there are stuff like Fox's twister custom which kills ridiculously early. Sheik's penetrating needles which can break shields given enough pressure is provided (a set up i've seen gsm VoiD do is throwing a grenade + penetrating needles which breaks shields instantly if they opt for shield and are in a bad position if they jump), Gravity Grenade which gives her a ridiculous kill set up, Rosalina's Luma Shot (falco laser basically) which gives her an amazing projectile, Luma warp, Crescent Slash, etc.
Also, I know we shouldn't exactly be bringing this up as we're all assuming this is all in a best case scenario, but it's not. Not everyone has a powersave and a 3DS to instantly get all the sets, and not everyone has the patience or time to sit for hours farming customs to use on their characters. I just don't see why we should allow unlockable items such as customs when we don't allow stuff like Smooth Lander or Heavy Gravity which are also unlockable items. It's exactly the same thing, and aren't really provided in normal play and not available for everyone.
And finally, no one wants to see custom villager time out all his matches.
A large number of customs are broken, they're not available for everyone, and I see no reason they should be used in standard tournament play.