I read a couple pages and found myself reading the same exact crap for a half hour. So I gave up.
All I have to say is that your ruleset tampers with the natural flow of the game. I will get to this in a bit.
As it stands the IDC has 1 application that must be called to attention, and that is its defensive purpose. Yes, using it to stall is taken care of but it can still be used for a split second to get MK out of a sticky situation. The ability to teleport quickly out of a bad position is in itself broken. Ignore all this SF comparison stupidity and just consider the fact that in an instant MK can reset the position to neutral. MK is a character that likes to approach, and the style that the rest of the cast uses is naturally to camp and wait for MK to approach and punish mistakes that MK makes while approaching. This is the only way to truly pressure MK. MK however, can undo all the pressure by IDC away. He doesn't have to approach with it or anything, he just needs it to stop whatever you are doing to him and then get right back in your face with his other moves.
Now onto game tampering. A lot of rules are imposed on the game to make things fair, banning of items, banning of stalling, banning of certain/all infinites etc etc. However, these bans are meant to ensure that the competitive aspect of brawl is held at a constant level playing field. What your rule does is give MK players the option to completely change the dynamics of the game.
Naturally, the game is composed of 2 characters fighting eachother, with the goal being to gain, maintain, and further a lead in damage/stock to ultimately win the match. They do this by attacking the other character and forcing the other to make mistakes. Despite differences in character playing styles and matchups, one aspect is held constant in all matches: Take more stock than are taken from you, and if tied stocks, deal more damage than is dealt to you. This goal is clear, it is universal. Your rule changes this fundemental in that the non-mk no longer has to take a single stock, or deal a single % of damage. He merely must survive. You suger-coat this by calling it a "risk" of a "campy" opponent. It isn't just a risk, it is a complete change in game dynamic. No matter how the match proceeds after the IDC is used, one thing is changed, victory conditions. It goes from fighting game to cat-mouse. This change will be in the back of both players minds for the rest of the match. The MK will have killing in his head, and the non-MK will have survival in his head. This is not theory. It is an easily provable FACT that the knowledge you have of the game will alter your playing style and mentality. I know DDD can cg me for 50%+, so I will emphasize not getting grabbed. I know I cannot reliably approach MK, so I will orient myself defensively. I know I will win if MK fails to kill me, I will try to survive. Your rule allows one player to change the victory conditions, and with it, the dynamics of the game and matchup. This is unfair. Are you going to find ATs for all other characters and say if they use it they must kill their opponent? If you cannot do this then the game implementation of your rule is unfair. And don't try to turn this back around and say that banning the IDC is unfair because it gives a defeat condition for MK. That argument is invalid for the fact that the IDC has a stalling application in itself which warrants a ban. You cannot solve the IDC stall problem and allow its use without changing the dynamics of the game.
Secondly, you create a specific rule modification in a specific matchup. Again, this is a changed dynamic. You are banning certain maneuvers in a certain matchup. Its like saying melee Marth isn't allowed to CG Falco but can CG Fox. Whats up with the exceptions here? MK can change the game up against all characters except for other MKs? In other words, MK gets to change the game, he also gets the priviledge of the game not getting changed on him.
Which character ends up having the advantage is moot point, the point is that the game has been changed. And the change is placed in the hands of 1 specific character.
Also, I'd like to add that bringing up the fact that no character other than MK has a guaranteed stall is stupid and redundant. We know nobody has a guaranteed stall, if they did the stall would be banned for the purpose that it stalls. Come to think of it, thats why the IDC is banned isn't it? Fact of the matter is the primary use of the IDC is indeed to stall. Stalling is not good, therefore IDC is banned. Once again, you cannot undo the stalling aspect of the tech without blurring a very clear dynamic of the game.
Also, you propose to ban IDC in any match where a non-MK could stall out the MK if the MK used IDC. I don't need to mention that said stall method would be banned. But I will mention that you are thus suggesting we give MK an AT that allows him to stall (I KNOW I KNOW ITS A BAD IDEA UNDER YOUR RULE, BUT THE POINT IS IT IS ALLOWED), teleport instantly out of any disadvantagous or perceived threatening postion at will, and disallowing it in any matchup where it would cause him to lose. Looks like MK is getting the long straw in everything here.
Note: Please note very clearly that I disregard the theoretical applications of the IDC, I address its known applications and your inability to solve them. Foremost is stalling, which I have explained carefully that your rule gives MK a choice in changing the matchup at will. ALSO, he can still use the move to stall. Bad idea or not, he can stall with it. Then there is the reseting of positions, he can go where he wants to go. He doesn't need to approach or attack with it, he can do all that already, but the IDC allows him to place himself in a position where he may be more comfortable, say from across the stage to just outside your reach if you're TL.
Finally, it is not our jobs to prove to you that Banning was the right thing to do. But banning does solve the stalling problem and does not give MK any uneccessary choice nor does it change the goal of the game. You are the challenger of the establishment, therefore you are the one who must provide the evidence and gather support. You are the one who requires overwhelming evidence. You are the one who must track down video footage of the IDC in use that is clearly not broken, you are the one who must host tourneys with your rule in implementation and prove that the IDC can be used and still foster competitive exciting gameplay.