Hi Ronin1966. WRT your question on what I consider "professional behaviour", here's a short list of the things I expect to see:
1. If you say you'd do something, do it. Deliver. Don't let your words fall to the ground. If circumstances may prove problematic, don't give people false hopes. (It all comes down to honor and integrity, basically.)
2. Honesty.
3. Willingness to teach, and sustain the school/club/academy/dojo/dojang etc, which ever term you like to use to describe your "school", The students are there to learn, they are not there to receive your wrath just because you're having a bad day/month/year. They are not there to receive flakey instructions that don't reflect the fees they pay. (Students leaving en masse may be a sign that something is not right. Have the balls to acknowledge it, and deal with it. Dealing with it does not mean banishing those who disagree with you, even when being impossible is so much easier than being reasonable.)
4. If something involves a business decision, then have the wisdom and discernment to turn to the right people for help. TRUST your friends, those who genuinely care, in other words not the McDojo salespeople.
5. Try your best to have no favouritism or unfairness. In a class there will always be students who are more talented. Have eyes and ears open so the mere mortals don't start to wonder why they're there.
</Rant>
In terms of having a "second job" - I'm neutral on that, because not everyone can live like a shaolin monk- train full time every day, and find time to study religious texts!
If it's not religious texts, then at least journals from the ACSM, or keeping up to date with relevant subjects on nutrition, training techniques etc.
As for a neural surgeon having a second job as a plummer - surely the person should be a heart surgeon!! I would have thought a neural surgeon would have a second job as an electrician, but anyway.