I love this! This is what I have been looking for in MU*s. It ties skill development to time rather than vague xp, and it creates projects for people to engage in while limiting them to how involved they can be. I think FutureMUD was going to have something like this but that project has gone quiet. It's also similar to Arx's investigations and tasks system, only all tied up into one streamlines system.
As for giving players benefits for playing, I have always said that if you have to be incentivized to play a game, it's work not a game, so why are you playing it?
The only bonus I consider giving players is something like "bennie points" or what Firan called CP. Turn in so many of them and you get a one to three scene GMed plot focused on one of your character's or a fancy item that doesn't give any stat boosts but looks nice and is unique, etc.
@surreality Yeah, some amount of flexibility might be a good thing anyway even if it increases complexity, for very specific cases.
For example you might want to have two rolls - a Persuasion one to convince Molly you it's okay if you just go into her boss' office for a minute to drop off a memo and a Subterfuge roll to make it sound like you'd be in trouble if she told on you ("sighs I forgot to do it last night, I'm so dumb!") to keep her quiet. Failure on either could produce different results - not being allowed into the office, or letting you in but telling her boss afterwards to cover her ass, or both.
This is kind of what the Doors system tries to represent in its short-term version.
Convincing her to go into her boss's office to drop the memo is one Door, and convincing her not to tell ony our for "forgetting" is another Door.