Heres a small list of suggestions, some of which are probably suggested before but oh well
-Miners don't get drowned or burned in channels that they've just made
This is more of a seconding, its occasionally a pain to not be able to safely make active channels.
-A substitute for Tantrum: On Strike
Perhaps instead of throwing stuff and pissing people off, very unhappy dwarves could go on strike, and perhaps incite other dwarves into doing the same. This means in an unhappy fort your entire operation could grind to a hault as everyone goes on strike. You could use military to silence the strikers, but doing so would create an unhappy thought in EVERY dwarf. A strike would end in one of 2 cases: necessity forces the dwarf to stop and obay, the threshold here would depend on how unhappy a dwarf is, a dwarf who is merely Unhappy might take up a sign for a bit then stop when (s)he has made the point and is running low on cash. A Miserable dwarf could go on an honest hunger strike because (s)he would probably starve anyway. The second strike ender would be if necessity forces YOU to stop and obay, say if you're about to be seiged and your only armor smith goes on strike, and you dont have enough armor for your troops, you might find yourself having to give the dwarf what (s)he wants.
-The opposite extreme: honest motivation
All ecstatic dwarves work at twice the rate as content dwarves.
-Slaves
Kobold and Goblins cought in cages could be, with the use of a Rope and/or Chain, and someone with the animal training skill, turned into slaves, who will work in any conditions without complaint or tantrum, until the day they starve.
-Native wrestling damage
This would make some creatures automatically damage you each time they make a wrestling move on you or you on them, this would be useful for fire/magma men, and any other creatures that would cause harm by touching anything. This could be a part of regular creature raws, the damage type and name of the damage, much like an attack string but using the wrestling situation for origin/hit location info instead of preset types and random number generation.
-Limiting of where attacks can hit
It's a bit of a stretch of the imagination to see how something could punch you in the foot if you're both standing up streight. Plus, some creatures tend to attack certain body parts, for instance, a Jaguar should have a tendency to start off its attacks with knocking you over and biting you in the neck if it comes from behind.
-Year displacement
This is more of something that would be cool-but-generally-useless. When modding, you could create a file with a year displacement. So say, if youre making a bronze age mod, you could put -2000 into it, making the starting year -950, or if youre making an industrial age mod, 800 as a displacement would put the starting year at 1850. It's simple addition to the number seen on the screen.
-Moddable processes
This could be a raw, you could have the building name, process name, ingrediants, products.