I’m a little bit unclear about the issue with toggling/dimmers. I think this might be a general OpenHAB issue rather than a Plum binding issue and something you can fix by tweaking your rules. I have a similar issue with my Insteon devices…I think… If I’m wrong and you think this behavior is specific to the Plum binding, let me know and I’ll take a second look! As far as I know, Dimmers in OpenHAB do not return their status as ON/OFF, they return it as percent 0 to 100. You can send them ON/OFF commands, but when you read from them or put a rule on them, the value will be a PercentType. If you have a rule that checks if a Dimmer is ON or OFF, perhaps you can change that to if a Dimmer state changed and then use an If statement to check the percentage. This might work a lot better when using native OpenHAB2 plugins, I dont know. Here are two link that show some examples: Slider not working with 1.8.3 - #5 by Flavio_Costa Dimmer Control (Z-Wave; GE 12724) - #2 by bob_dickenson
The motion sensor stuff is really cool, but my implementation isn’t particularly flexible nor reliable. Next time I work on the code, I’m going to try and improve the behavior of the motion sensor items. Sadly with a lack of documentation from Plum, it is a lot of guesswork. Still though, it is good enough to have some fun with. I use it in a few places and it is better than nothing 
Messing around with the glow ring is pretty easy to do. I already have some really rough code that can do it. First step would be adding it to my plum-probe.py script so that people can play with it. Next step would be adding it to the OpenHAB plugin. I’m not very knowledge about the Color item type in OpenHAB but I suspect it could be exposed as one of those. I can definitely give this a shot some time but I’ll be honest I’m not exactly sure when I’ll have time. Could be a week or a month.