Can I use field scripting to have the first letter of a field use a different font and/or font size?

This can be accomplished with VB scripting.  You would use a script like this:
"<font fontname='z' fontsize='x'>" & left(fieldname,1) & "</font>" & substr(fieldname, 2, 9999)
You would replace z with the font name and x with the desired font size.  You would also replace fieldname with the actual field name.