I might be in the minority's here but I like the Treasure Key mechanic the way it is. There's no way in hell I'll grind Patrol for hours every week trying to get some. But it's good to offer people who have more time to put into the game these additional opportunities.
I'll still have NF x3, Gorgon's x6, Atheon x3, Deathsinger x3, Crota x6...that's a damn heck of a lot of Exotic rolls. No way I can do all of those every week. For the guys who knock that list out each Tuesday at reset, the possibility of rolls hinged on a super rare drop from an annoying disappearing chest sounds fair.
PoE will still give me cores and Etherics and fun, more than enough reason to keep running it.
The systems you guys suggest with lots of guarantees Keys per week would mean changing the treasure's generosity. Chances at Exotics are sooo high, with some people getting 2 Exotics at once. It's cool that it's there and I guess it's meant to be something most of us experience perhaps once or twice a month.
Hardcore players with tons of free time can experience that every week, perhaps multiple times. Seems fair