Wow...this post made me think I shouldn't even attempt to run my own server infrastructure for my startup. This kind of analysis is way deeper than I'm currently capable of.
It truly is a joy.
I also forgot to mention we have a build server, but thats just a virtual machine that we backup regularly. It's our only piece of static infrastructure. Everything else, except storage which is, again, transparent to us, is destroyed on a weekly, if not daily, basis for new releases.
I think, fundamentally, files are the wrong abstraction for log data (as pointed out by Adam Wiggins of Heroku fame: http://12factor.net/logs), but it is something that we are stuck with.