here are some things i've come up with.
every large fortress usually has several injured dwarves. severely injured guys can just lie there for years and years distracting other fully functional dwarves from doing their duty by constant demands of food and water. and generally once they go "red" they never go back. so why don't we make a hospital? a room, toggled from the bed, where dwarves would pile all their wounded. then we might have a new profession - a dwarven doctor! this dude would use alchemist workshop (otherwise used for soap only - what a waste!) to brew some dwarven medicine (not ale), attend to wounded (feeding them and stuff) and generally help them recuperate faster. he will also be essential when the plague strikes down upon the fortress.
my second suggestion is temples. well, maybe not temples but at least some kind of altars. which brings a new type of nobility - priests. though priests might also be a brand new type of their own. so we'll make up a bunch of gods, each standing for some sort of social activity (god of war for all kinds of soldiery, god of fertility for farmers, herders, hunters and all such stuff, god of crafts for all kinds of craft, etc.). for example, the priest of fertility might well come into your fortress accompanying the house Ber representative. then they demand an altar and a small room to live and pray in. their further demands would be somewhat more obligatory than those of nobles, like if you don't fullfill priests demand to create three marble idols to sacrifice to the gods, this may grant bad luck for your farming (vermin, meager harvest, food rot, etc.). on the other hand, if the sacrifice is made properly, gods smile upon you, sending you some goodies (like your cows bring twice as much calves next year).
what do you guys think?