I shoot events (>50+ todate). Just share some thoughts which I hope will he helpful.
1) When you are asked to be the photographer for the event, do you know what is your 'brief'? i.e. are you required just to take a few shots of your boss delivering a speech so it can be featured in the company newsletters, or are you trying to cover the entire event and provide some kind of a 'record or story' of the entire event. If just for a shot for the newsletter, I can't imagine you having to shoot hundreds of flash shots just to get a couple of pictures. So know what your brief is.
2) Yes, it can be quite irritating for the VIP is flashes are fired indiscrimately and at too close intervals. It may even distract him. So shoot discreetly if possible. Longer lenses are better. Wait for the 'right' moments, gestures, smiles, or when he is emphasising a point or something - capture that moment instead of shooting like a machine gun.
3) Regarding employee or boss, etc. when you take on the job as the photographer, think of yourself as a PRO on assignment. No need to be apologetic. Your job is to capture the moments and deliver the shots that you have been tasked to do. Of course, no harm saying 'hello' and introducing yourself at the appropriate opportunity.
Hope this helps.
Fred