Long post, TLDR version upfront: Tomislav nerf is unnecessary, Reserve Shooter should only belong to Soldier, Widowmaker is now useful but still directionless, Enforcer is still overpowered, and who cares about the Claidheamh Mor
Tomislav
I know it's something close to unwritten Scripture that the Tomislav is massively overpowered, but I think there's a reason Tomislav Heavies haven't been steamrolling every game for the past month: it's not overpowered. Granted, the weapon was more effective at direct combat than it was meant to be (the now infamous increased "effective DPS" where Tomislav beats Minigun if they both start with full health and unspun) so its niche as an ambush weapon was lost in the mix because it was too easy to use for unskilled players. The fast "spin" time essentially made it an unofficial assault rifle, which has always been my main problem with it.
It actually reminds me of the Liberty Launcher and Black Box, i.e. an easier, weaker version of the stock weapon that can make the class more effective in certain situations or in the hands of a novice. For even semi-skilled Heavies, though, the Minigun is still far better, which is why most Heavies on good servers don't seem to touch the Tomislav much. If you can manage to get the drop on your opponents - one of the key skills of playing Heavy - then the silence and fast spin up are somewhat irrelevant and greatly outweighed by the lower fire rate.
So, yeah, long story short, the -50 health nerf is less needed for gameplay than it is to silence the booing crowd of people who think it's overpowered. Most of these people think the Heavy's overpowered overall anyway, so I don't see how nerfing the Tomislav will help much. If you want to fix an overpowered Heavy weapon, start with the GRU or Sandvich, ones that actually do make him an unstoppable juggernaut.
Reserve Shooter
Everybody's already said why this should stay with the Soldier in terms of art style, and while I agree with it wholeheartedly, the main reason the Pyro should keep his creepy Frankenstein hands off this beauty is that the Pyro already has a vast assortment of fast, deadly combos to choose from. Between the Degreaser's quick-switch, the Flare Gun, the Axtinguisher, and the airblast, the Pyro has at least a dozen ways to whip out a Street Figher supermove (Hadouken!) and kill in two seconds without usurping the Soldier's.
The Reserve Shooter is a perfect sidegrade: a weak, highly situational weapon that rewards fast response time (the quick switch isn't that much of a boost, after all) and the skill of rocket juggling, as well as providing Soldiers a fun way to counter each other's rocket jumping tactics. The Pyro requires next to no skill to get someone into the air, just W+M2.
Also, the Reserve Shooter has a time limit on its minicrits to keep the Soldier from getting kills with it unless they've already done damage with a rocket. You can't switch back and forth from Reserve Shooter and Rocket Launcher fast enough to reset the timer. With the Degreaser, though, you could do this easily, even without the Reserve Shooter's own quick-switch bonus. I know it has a three shot magazine, so that would keep this from being too easy to pull off, but Pyros are already built around such fast combos.
Widowmaker
The reduction in metal cost is a much needed fix to an utterly useless weapon, especially considering that the Engineer got nothing in the Uber Update and the Deus Ex gizmos are the closest he'll probably ever get to the Teslaesque electro-guns that everyone and their dog wanted him to have. However, the purpose of the weapon is still unclear: what play style does this metal-as-ammo mechanic appeal to?
The Frontier Justice has a clear purpose, i.e. allowing strategic use of the inevitable destruction of sentry guns, and even the Short Circuit has a niche as a projectile eraser for support Engineers protecting large nests. The Widowmaker simply rewards Engineers who get kills with their shotguns by giving them metal, but since they can't get more than 200 metal anyway, this is hardly different from the stock Shotgun, which doesn't touch the metal at all. I can imagine certain Engineers who might use it as a quick defense weapon (kill a Spy, use metal received to repair field sentry) but it's still muddled.
Enforcer
Unless they change how it works in conjunction with the Dead Ringer, it wouldn't matter if they quadrupled the cloak time because Spies would still use it as a frontline, no-disguise weapon for taking out enemies from the front. It's not the downside everyone thinks is broken - as it's already pretty bad with a regular cloak - but the huge damage buff that makes the Spy's already powerful Revolver into one of the most accurate, powerful, and reliable primary weapons in the game. To put it another way, the Enforcer is annoying because it removes the need for the Spy to rely on his cloak, disguise, knife, and sapper, since he can get regular kills and destructions with the pistol alone.
Claidheamh Mor
The buff is needed to make this a viable substitute for the Eyelander, but unless you're in Medieval Mode - which is inherently for just goofing around anyway - this is still an inferior choice for a Demoknight than either the regular Eyelander or the Persian Persuader, which refills the charge so fast anyway that the minor one second buff for the Claidhmeah Mor still grants less net charge ability.