@Joseph_Marrone Good question!
In short, this shouldn't cause any problems.
As we mentioned during the Q&A of the webinar, we decided to use Python 3.6 for Dronecode because this means we can make use of the new Python
asyncio functionality. This makes it possible to offer a good async interface as well as a sync interface on top of it.
Now this is just our current suggestion, if many (like you) are not ok with Python 3.6 and later and really need something with Python 2, then we can certainly revisit the decision.
I don't see a problem with having different Python versions for different software on a machine. It's quite common that some things run with Python 3 while others are still using Python 2. So in our example, the tooling around PX4 can still be in Python 2 (even though it generally also works with Python 3).
Also, for Python dependencies (things installed using pip) it's generally recommended to use a virtual enviroment to avoid dependency conflicts.