Bobby, you said every app is a client of the API. I notice Trello.com consumes API from https://trello.com/1/xx while an OAuth client (from one of your Jsfiddle examples) consumes from https://api.trello.com/1/xx?key=xx&token=xx. I suppose the former just passes through to the later? If so, does the former needs to pass over the key and token (I suppose you can generate on the fly based on auth cookie)? I'm trying to get my head around the fact that your app provides OAuth for other clients and at the same time (from what you're saying) your app is also one of such clients. Not sure how it really works.
And are these 100+ engineer forced to accept that term? Or more likely they think it's a good deal for them (i.e. living in India earning Indian wage)?
One technique that I used when building my own progress indicator is using a maths function which approaches 0 as the progress bar approaches 100% and use the result to increase the progress.
A couple weeks ago I built something similar, except that my solution is even smaller (doesn't depend on jQuery, 1 single file, 1KB gzipped and minified). Check out: http://buunguyen.github.io/rainbow.js/.