1) That is planned and will be added soon, it is a very good idea.
2) I have no idea why we don't do this already, we'll add it straight away!
3) We will, but right now we will be changing backends, so we will document the new one (probably Sphinx with EXTENDED2).
We don't reindex documents, as they are cached and never change (when you bookmark something, the bookmarklet sends the source to the server, which is how we can bypass registrations and paywalls). Plus, you need the document to be as you remember it.
We currently use Whoosh with Python, but it turns out to be excruciatingly slow. We will change to either Sphinx or Solr.
We don't know why the extension does that :( We can't reproduce it on any of our computers, but many users seem to have the problem :/
Three suggestions:
1. Add a snippet with the search terms highlighted
2. Show the date bookmarked in the result list and (if possible) the date of the last update.
3. Document the query language for extended queries
Two questions:
1. Do you reindex bookmarks after some time?
2. What indexing engine and platform do you use? (lucene/java?)
One remark:
1. The Chrome extension is unable to bookmark sometimes. The bookmarklet is working great.