Correct: this is expected, there’s still no new server version to download, and the disconnection could be temporary (for example, it’s what happens when you Pause Sync - resuming it doesn’t trigger a Client Reset). The SDK just holds all the local modifications, periodically polling the server, until the connection is back.
In isolation, no, but think in terms of thousands of users active at any given time, that are trying to connect to a server down for whatever maintenance was needed (or just a data centre offline for a bit). The server will need to spend time just answering back with errors.
That’s correct, see my answer to a similar question.