1. Resolve was removed because it caused serious balancing issues where some builds were overly powerful (because you could usually knock down that bar far faster than Health) and it caused issues with party composition because unless you had all your characters targeting the same bar, at least one of your characters was basically wasting their time. The new approach lets everyone contribute regardless of what they're doing because it all goes towards the same bar, while there are still differences in damage for sexy attacks to give people who focus on that an edge against enemies weak to Horni.
2. It was capped because past a certain point it could be used to do some pretty ridiculous money-earning exploits and past the point of the new cap it stopped actually
doing anything to increase your Champ's chance of impregnating anybody, so the net impact is precisely nothing.
3. If you haven't played since before the Resolve removal you've missed several major changes to the combat system that would take a long time to describe in detail. See
these patch notes and
these for a summary of the biggest things that have changed. Assuming that you're playing your Warrior as a tank (which is what they're meant to be) then yes, they've gotten much scarier due to a combination of the changes (like Stances auto-activating at the start of combat) and the new Level 7 Perk abilities, of which there are now two per Class that you can choose between. One of the Warrior ones grants a blanket 20% resistance to all damage types which is awesome for absorbing damage, while the other deals a percentage of your normal attack's damage to all other enemies should you be playing more aggressively. All the new Perks are pretty build-affirming so whichever Class you're playing, you'll like them.