To be really safe you should never even think of not wearing your hi-vis vest when engaging in any activity on an airport, the hi-vis vest is number one priority in my opinion.
Yes, of course. In addition to confusing rules, petty but determined and invasive do-gooders, discussions about the exact way in which one should obey rules (if it can be determined what they are), and on-site comments that other participants are "not short a quid or two" all aviation activity must surely include appropriate fancy dress.
Preferably brightly colored and festive uniforms, of which the reflective vest is a perfect example.