The early '90's hondas did have distributor issues and they can get loud if the bearing is going. A low mileage car like yours is nice to find, but can sometimes have issues from not being used enough. You rough idle could be a vacuum line with dry rot. Or, an easy check is of the IAC (Idle air control) valve. It is mounted right below the area that say PGM-FI on the throttle body. There is a screen there on the valve that can get clogged. Spraying some throttle body cleaner on it to clean it off may do the trick. I had mine get some carbon buildup and once cleaned my idle returned to smooth.