Earthmover
Good post, and as a dispatcher I look forward to the replies. It would be good to see some kind of best practice evolve from the discussion. I think perhaps too many gate staff/dispatchers fail to consider the safety aspect you mention, and instead focus on the likely occurrence of airborne mischief.
Not had to offload any drunks yet myself, but warned the number one and captain on a couple of occasions of pax who are suspected of having drunk more than is sensible, after a heads up from the gate staff. All have seemed OK to me, and crew happy to accept, and so far no adverse feedback.
I also put sneaky smokers in the same category, if they have been seen or suspected of lighting up in prohibited areas. If the crew are happy to take the risk of accepting them, then after a lecture from me, they get on board. Interested to hear other's views.