IMO we should be able to vote non-staff members if we wish, because the selection would be too limited if we could not vote them. IIRC the people who are promoted to be a staff is probably from the opinion mainly from the higher position. even this could result in the mass registration of election, at least it could decrease the suspicion of biased nomination.

if we neither could vote for our loyal representative, join the nomination freely, nor if the number of votings could reflect what the majority are expecting for, including the balancing of the minorities, the result could possibly result in staff system disaster.

one more thing, global moderators elected are responsible to the happenings more than what we are required to address, not only monitoring the site.