It's too early to say how long resource credit (RC) delegations will take, but I guess we'll have some idea in a couple of weeks. @howo is going to research this task.

I'm a little more skeptical of the immediate impact of RC delegation, however. In order for an app to want to power up to supply RC for a ton of users, it first has to gain those users. So I think that will be the primary challenge (creating an attractive app for the masses).

I'm not terribly involved in the marketing side of things, but there is a marketing proposal right now, and I know they are always looking for people to help out.

It sounds like you're talking about some kind of "grass roots" marketing proposal that pays out to people who market on other platforms. To some extent, I think we've seen large stakeholders already do this, by sending posting rewards to people who participate in such campaigns.