It is required to read tool by tool and install their dependencies and configurations.
Just running fastlane deploy --trace causes the process to hang at the snapshot step.
It is a really cool tool and I will definitely use it, just the documentation needs to be clearer. Good job!
You are right, installation is not super easy right now, due to Ruby dependencies, which also depend on Nokogiri and phantomjs.
Have you seen the guide, that helps you with getting and up and running quite quickly? https://github.com/KrauseFx/fastlane/blob/master/GUIDE.md
I tried this on a fresh Yosemite installation, and it went quite fluent.
Let me know if that helps you and how I can link the guide better to make it better visible.
For example first get the gems installed and with that you could just add to the lane the increment build number.
Then install homebrew and xctool and add that tool to the lane.
In that way, you can start using fastlane gradually and not install all the dependencies at first. It is the approach I would take, but I know there could be many others for such a complex tool.