You cant do if/then statements in roll20 macros. There might not be any way to do your step #2 without the API (a Pro subscriber perk.) There might be a way using complex nested menus, but that way lies madness. If anyone can do it, Ziechael can, but you'd need to be very specific about the requirements. Don't be vague: say exactly what the attributes are, and exactly what the conditionals are. The more information you give, the better.