I don’t mind helping, but at this point I am guessing.
You are taking note of the potential pymavlink conflicts with dronekit? Have you run this in virtualenv?
https://dojofordrones.com/topic/installing-virtualenv-for-multiple-pymavlink-versions/
What are you getting for -
pip freeze | grep -i mav
pip freeze | grep -i drone
I noticed a previous forum discussion on this..
https://community.dojofordrones.com/t/launchsitl/321
Can you communicate with the sim_vehicle ok just with mavproxy commands?