Decided to just dive directly into the fire... not using anything easy or sensible like Zwave, but rather a Plumlife lightswitch on a totally new v7 installation, having never before used HA before.
I can control and retrieve the status of the switch at the shell with several Python commands ("plum-probe.py --logical_load_id xxx-yyy-zzz --status" to get the status, while replacing --status with other arguments such as "--dim 80" or "--off" or "--on" for control. Easy enough at the shell level.
How do I pass those parameters on within Indigo. Found that I can't seem to create a device with this newfangled switch, so I found that I could do something with Action Groups, within Server Actions, but I'm sure I've got it all wrong.
Further adventures will include creating input variables for "--logical_load_id" and "--dim" so I can do something with more than just one switch and setting, and then creating variables from the resulting JSON string returned to actually get some feedback.
Anyone want to nudge or push me in the right direction? I've done quite a bit of searching and reading, and I'm not a stranger to programming, but I'm a bit turned around at the moment.