re: Poker & Mid size flush hypothetical
Generally its 50/50 for me, if I detect a lot of weekness I will semi-bluff with a fush draw. Usually only about 1/2 to 3/4 of the pot. If I get raised big I will fold if not I will wait for the next card.
Just taking another free card or check/calling a bet that gives me the correct odds
to keep chasing the flush is also a fine move.
It all depends on the table, when I play live the flush draw raise is pretty normal with the knuckleheads I usually play with.