It’s not clear to me if I can run other services on openHABian. I have PiHole and some other smaller services running on my RPi. Let me know if other non-standard services can run on openHABian and I will check it out.
Okay - let me rephrase it:
As the maintainer/dev HABApp will always support this because that’s how it works. 
You don’t have to rewrite all your rules - HABApp doesn’t get in your way.
If you want to you can only rewrite the System started part.
Full IDE checks and auto complete support. I use PyCharm and it is exceptionally good.
Well we recommend against doing so because other services are also always a threat to openHAB’s availability, and because people easily screw up things when they install additional stuff, plus it greatly increases support efforts on our side, plus some more reasons. But technically, you can.
Thanks for the info. Sounds like there’s a learning curve for me regardless. I’ll keep this as an option.
That makes sense. The next RPi I pick up will be for openHAB only and I will give it a shot. Thanks for the info.