I've been using ghost for about a year now, more or less, starting at a pre-release version. Migrating from 0.x to 1.x was a pain-in-the-arse, and the first few .x releases were difficult until I wrote down what needs to happen. Not sure that a script is called for because there's not much to it and doing it by hand helps me have confidence that any errors or changes in the process that the ghost developers introduce upstream are noticed and don't become catastrophic (having to recover content from Google cache sucks).
Anyways, my process keeps my cleverly named theme "keith" which enables QR Codes, and, the S3 plug-in. If you don't have a custom theme then skip the "
rsync .../theme" bits. If you aren't using S3 then skip those bits.