Chrome's basic development page was almost helpful enough to get everything done. A critical misunderstanding was cleared by founding out a question/answer from StackOverflow.com, though if I had read the whole Chrome page, I wouldn't have had that problem either.
In that site, there's sample applications that are neatly put in one page with links to API. Also the Hello world application was just what it needed to be. Overall the site is solidly done. However I would have liked also samples that weren't fully functional with particular aspect in mind. Or maybe FAQ. By the way the problem I had was opening new tab with existing resource. It was directly doable as a popup but not as a new tab. The latter needs function calls instead of configuring init file.
The extension architecture looks solid: one has a background script that stays alive behind the curtains, so to speak. Message passing is in important role; you use them to localize script environment which makes sense security-wise but also forces user to separate the app into components. The API seemed straightforward and has lots of callbacks using higher order functions. It is a beautiful way to propagate events. Maybe in some cases the code can have too many inner functions but that's mainly my own fault for using anonymous functions.
Debugging felt somehow harder than normally but it's probably because I needed time to understand how things work. Anyway, Chrome's basic development tools provide enough to understand simple problems.
Public deployment of the extension via Chrome's repository would be probably easy but I haven't done that yet. I first want to make the app solid so that people won't rate it poorly. Later versions would suffer because of it.