Very cool. Big up, Mr @Smoothie
Some concerns:
To avoid pay-to-win, the rules should be Ironman; after all, making a competing account Donator(+) and/or trading over tank gear and supplies also constitutes pay-to-win.
Donator(+) status didn't matter in the competition on skilling release, because the new Donator Zone wasn't yet added - obviously, it does matter now.
Feeding an account gear/supplies was abused by the winner of the previous maxing tournament (he was fed and protected by a clan).
Clans, or a clan, could feasibly lock down all the Wilderness methods (including those that avoid the Resource Area), given that skilling has been out for some time now and even the alternative methods are fairly well-known.
Woodcutting and Agility, in particular, could be extremely difficult to train efficiently.
Not sure how you could realistically combat clans dominating the competition, but they will if they want to.