Feedback Wanted!

I'm looking for all kinds of feedback; on the code, real world use cases, feature requests, etc....

Oh yeah, does it work for you?

From the Go community.

This is my first piece of go code. I'm sure there's lots of room for improvement. Things I know I want feedback on:

variable and function naming
structs vs. pointers to structs, consistency and sensibility
Could I have made better use of templates?
documentation, go doc

From the Terraform community

Thoughts about parsing state files and grubbing around in resource data.
What should I use in AWS for a name, and for group/hostvar info.
What should I use in DigitalOcean and Cloudstack providers for groups/hostvar info.

From the Ansible communtiy

Should -i 'roster inventory' work? There's an ec2.py example in the docs that suggests it should, but it does not for me.
is it worth making roster inventory --host=moose.example.org do something more than spit out {}?
Could I have made better use of Go templates?