scenario 1, i lead out this flop almost every time.
scenario 2, i mix up leading out and c/c or c/raising (only if opponent is known to always bet when checked to in position)
scenario 3 i almost always check when i dont have a redraw to the flush. i do like to float a flop bet and c/c to get a cheap showdown assuming the 4th suited card doesnt fall on the turn/river.