Firing an employee for making a pass at a boss's spouse is reasonable if the relative tries to personally betray the boss.
It would also be reasonable, and legal, to fire an employee for kidnapping, sheltering an evil twin, or blackmailing their long-lost uncle.
When an unpaid volunteer is not responding to inquiries, then at some point, assume they're not doing the work and make other plans.
Set clear boundaries and politely decline social overtures if a colleague tries to befriend you after an unpleasant past altercation.
It is best to politely redirect people who want free advice to pay you for it, or refer them elsewhere for pay.
Cover letters with instructions to readers like “If you did, write ‘Booyah’ at the beginning of my follow-up email. Because you did what most don’t!” are unprofessional.
It's best to ignore such letters and not give feedback as it's not the job of the employer to coach them.
The rise of applicant tracking systems can leave job seekers frustrated with the lack of response from employers.