Personally and IMHO, I think that the use alternate fonts/styles in general posts are a cry for attention (the exception being
Famine, whose encyclopedic plethora of information, both pertinent and arcane, begs for it.

)
Special fonts/styles have their place, such as in Race Anouncement threads, Race Result threads, other comps such as the Photo comps, etc., and in announcements and, when tastefully done, in sigs.
Online text in general threads should
always be san serif, since it appears backlit (by the monitor) and is easier for the eye to follow in backlit conditions. Serif fonts are intended and best suited for printed documents, as the serifs help the eye to flow through the text better in written, frontlit documents.
Changing fonts from the default, especially to a serif font, in a post also disrupts the flow in a thread, and is distracting.
Sidenote: At every forum I've ever been a member of,
asking to be an admin or moderator before being asked is a sure fire way to guarantee that it will never happen.