Can you repair plaster with drywall joint compound?

yes you can roll on joint compound but that is usually done when you want a textured wall or cieling and does require a great deal of compound to use-- it is also a slow tedious process since the compound is thick and not so easily movable. If you are looking for a textured wall or cieling my advice is to first trowel the compound using a 1/4 inch toothed trowel and then roll it out with the texture roller. you cannot use a paint roller to roll out joint compound. There is a special textured vinyl roller for this purpose it looks like a roller created from a spool of wire.