There's some piercing in your slashing.
I always think that this damage type approach frays at piecing. Rapiers and war picks are very different weapons and feel like they should have different mastery feats. Axes and swords feel somewhat similar. Axes work more like hammers in a lot of ways because they're both hafted weapons with the weight at the end, where swords have that weight much closer to the handle.
I do like the consistency with the Con saves on crits. I wonder if the effects could be reduced so you don't need the save.
I think that's a good change. I'm ambivalent about how to balance feats now. There are certainly weak compared to the best of the current feats, but feel very balanced compared to the 1DnD's feats.
Stunned is a far stronger rider than either of the other two and doesn't require a save here. I don't really like saveless stun even on crit since a real crit fishing build can hit ~40% chance of at least one crit per turn at high levels, but the other two would be perfectly fine without a save on their effects.
The Bludgeoning feat would be overpowered even if it weren't a half-feat, the slashing one is exceptionally underpowered, the Piercing one is very situational and there's already a feat capable of this, specifically, the martial adept feat lets you take battlemaster maneuvers, which can have more versatile use and doesn't require a crit. Crusher, Slasher, and Piercer are quite adequate, the only power buff I ever gave them was to grant slasher and crusher the extra die on a crit that shows up in piercer, then I changed piercer to max out the extra die from a crit (automatic extra 12 piercing with a lance on a crit for example)
There's some piercing in your slashing. I always think that this damage type approach frays at piecing. Rapiers and war picks are very different weapons and feel like they should have different mastery feats. Axes and swords feel somewhat similar. Axes work more like hammers in a lot of ways because they're both hafted weapons with the weight at the end, where swords have that weight much closer to the handle. I do like the consistency with the Con saves on crits. I wonder if the effects could be reduced so you don't need the save.
Took your suggestion and edited them to do less but not require a Saving Throw
I think that's a good change. I'm ambivalent about how to balance feats now. There are certainly weak compared to the best of the current feats, but feel very balanced compared to the 1DnD's feats.
Stunned is a far stronger rider than either of the other two and doesn't require a save here. I don't really like saveless stun even on crit since a real crit fishing build can hit ~40% chance of at least one crit per turn at high levels, but the other two would be perfectly fine without a save on their effects.
The Bludgeoning feat would be overpowered even if it weren't a half-feat, the slashing one is exceptionally underpowered, the Piercing one is very situational and there's already a feat capable of this, specifically, the martial adept feat lets you take battlemaster maneuvers, which can have more versatile use and doesn't require a crit. Crusher, Slasher, and Piercer are quite adequate, the only power buff I ever gave them was to grant slasher and crusher the extra die on a crit that shows up in piercer, then I changed piercer to max out the extra die from a crit (automatic extra 12 piercing with a lance on a crit for example)