Luckily it is only the minority of Capts that are difficult. Most take advice well personally I'm glad to have a FO to catch all the balls I drop, I've only made one buy the alcohol free beer all night.
You need to speak out as FO, it's your job. If we were all as perfect as some as the 'old school' BOAC Capts there would be no need for anyone in the RHS.