For 1 - Ya I also think blue is good for title color. i changed it some time back to black will revert back to blue.
2 - due to lack of data results are not good, crawler is continuously running, once we have enough data, that wont be a problem.
3 - for cloud apps - you hit exactly on the point that's why we added cloud apps, to target specific site or app you can choose app name in query like "s3 credentials from bob evernote", it will do the trick for you until more usable is developed.
4 - Yes chrome extension installation is bit tricky but right now don't have anything more innovative will figure it out. Search form on home page is symbolic, its not actual search. Initial idea is to take user to search page, definitely club both the pages to single one, like most of search engines are doing.