Your argument here is full of holes and hypothetical assumptions. Saying the mere transference of gil (minus whatever % the AH keeps) is somehow adding to the gold sink of the game is flawed.
For starters, whats to stop a greedy gil hoarder from buying up his own "sub token" and fattening his pockets even more? Also, do you really think only the 1% will be able to afford this? Wildstar sold their CREDD for $20 and they sold for anywhere between 15k and 20k. Thats next to nothing to high level players there and easily obtainable in a few days. I even read posts of players claiming to have multiple months worth of CREDD tokens saved up. Anyone greedy enough to hoard such amounts of gil could easily use this to hoard even more. Not to mention how the fact you only need one of these per month means it would hardly make a dent on the filthy rich.
Second, just because Player A buys a sub token from Player B doesnt automatically mean he's going to now spend all that in gold sinks. What if he becomes the gil hoarder now spending his hard earned RL money to become the new 1%er? Everyone has the same gold sinks available to them ... thats why theyre there. Everyone needs to repair, everyone who buys in the AH needs to pay the tax. I dont understand why you think the rich have any less of a gold sink available to them than a regular player. Sure, Player B may suddenly be able to buy a 2.5 million gil house, but those arent exactly readily available are they? SE cant even keep up with demand.
Third, what one player does, affects the other. Maybe now that Player B has all this gil, he'll craft even less. Why bother leveling and crafting things to sell when you can just pay SE and you get a hot ticket item and sell it for a large amount of gil? So now someone else has not only less things to buy, now he's seeling less mats. Yes, im building assumptions just as big as yours but both are just 1 of thousands of alternative consequences that can happen which may or may not make things worse. The only way to really fix inflation is with real gold sinks in which players want or need to spend gil on.
THis idea is good on paper for the possible effect it could have on hackers and bots ... however thats already been proven ineffective. Whats left is a 'legal' way of buying gold.