No sure if my vote counts, but a [x] +1 approve from me. I built the tag 6.0.0 locally with Go 1.11.5 and tested against a CS 4.5.2 and a CS 4.11.2 instance.
Listing VMs and stopping/starting instances works as expected, on both CloudStack versions. I also filed a few minor issues on Github, but nothing critical. The -p argument bug should be fixed in the next release if possible, though.