Different answers to different questions.
In theory, most of the plugins' documentation describes what variables they create. The name of the variable seems to tell me what they mean; are there some you're confused on?
To do lights at a certain time, you could use MLScheduler.
To make an Insteon button perform a function, you'd configure it from the MLLighting plugin. Select the device, click "Control". Select the "Control" tab. Use the wider pull-down (not the one that says "Level") and select button you want to make control something. Press the "Add" button on the bottom left. Select the state to cause the trigger, then type in the command or command-map to trigger.
For example, I use an "ALL" trigger on a C button for my AV.Volume.Office.Down command and an "ALL" trigger on a D button for my AV.Volume.Office.Up command. This makes those two buttons be simple volume control.