I'm guessing your New to the forums. First off you might want to avoid suggesting stuff that's already planed, (IE. personality rewrite) second, !!fun!! Is always welcome on these foums.
Also nonlethal fistfights and and other actions are also planned.
I am aware of the upcoming personality and combat rewrites. I have not seen a detailed list of all the new factors and aspects of said rewrite.
Just because nonlethal combat is available, does not meant that a tantruming dwarf will choose to use it, instead of putting his fist through the mayor's skull.
If fists get nerfed into the ground (at least to the point where a punch doesn't shatter bones like so much glass) then no problem there either.
I have no problems with tantruming dwarves beating the stuffing out of other dwarves, but when one dwarf can spark off an entire spiral by killing the beloved mayor in his first and only, unarmed attack, that's a problem.
Also, I have no problems with !!FUN!!. It's one action out of your control destroying an entire fort that I have problems with.
Soldier dies in combat or even accident, one family member tantrums because you don't have royal palaces for every dwarf yet, kills a beloved dwarf, goodbye fort.
It's the reason why I always rely on trap hallways and only ever make a squad or two of marksdwarves that I mainly use for cleanup. If you send a squad into melee, lose a dwarf or two, especially early game, you might as well kiss your fort goodbye, because you won't have the goodies required to prevent that kind of tantrum.
One of my forts, I had them at nearly ecstatic, running for about 10 years+. Everything was going fantastic, survived seiges from frost giants and even a dragon. Automatons get into a side passage, my (idiot) soldiers charge. Even though I killed them all (thanks to three fantastic swordsdwarves), those three dead soldiers made everyone depressed. By next season, tantruming dwarves had killed almost a dozen other dwarves and I was in fullblown spiral mode. Not a damn thing I could do about it. 80% of the fort miserable and even with a hoard of masterwork food, drink, individual smoothed rooms(was waiting for engravers to get to legendary before engraving the rooms), legendary dining hall, etc. It would have been salvageable if it wasn't for the fact that every tantruming dwarf ended up either maiming or killing another. The final nail in the coffin was, predictably, a single punch into the much-beloved mayor's head.