My 2 cents on RANKED ONLY:
Prizes/Rewards; Top 3 Players get a random item + # of tc (Thinking around 20k each? Seeing as it is a weekly thing and not a daily thing) Players between 3-10 would just get # tc (15k sounds like a good number.) then 11-15 would also get # tc (5k-10k.)
Mods; Add a "Featured" mod into the mix that is changed every other week. (E.g. this weeks featured mod is mushu but the week after nexts featured mod is lightninglenshu.) Other than that I like how it's entirely random.