IMO while I like both classes in the idea, IMO neither class is particularly well designed. Warlock in particular has some really nice aspects and is a good way to represent a character who’s got kind of difficult to classify magical powers, but it’s incredibly dependent on the annoying short rest mechanic.

As I said elsewhere, I don’t really like the bard as a full caster. IMO that’s a really uninspired design choice. “Let’s see, we’re not sure… screw it, let’s just make them a full caster and let people pick from the spell list.” I wish they’d been a half caster and had more thematic powers without having to refluff spells into songs, poems, etc. For instance, having the bard be able to sing a useful battle song—but only one at a time at first—which would give party buffs would be nifty. That’s how the bard in the Infinity Engine CRPGs (e.g., Baldur’s Gate II, Icewind Dale) worked. But slot burning to grant bonuses would work too.

Warlock having more slots and being a debuff specialist would be nice. WotC put a bunch of feat taxes in the way to make the warlock really able to debuff. I disagree about the various smite spells, though. The warlock does need something, though, if you want to build a non-Eldtrich Blast spammer, such as a melee warlock, at least without having to do one of those somewhat tortured multiclass builds.

Bard is a full progression caster, which creates a different situation than paladin. Even the Valor bard isn’t really going to be using weapons all that much until she picks up her archetype capstone due to built-in cantrip scaling and the debuff components they carry. I think there would be ways to do it, but it would require a lot more work due to the full progression and the options bard has at its disposal.

I don’t like warlocks having a straight lift of divine smite because the warlock doesn’t need raw damage. If they had done something to complement the core class – either picking up selfish-buffs or wider debuffs – I’d totally be on board.

I think the “burn spell slots for something” mechanic could be used more broadly. For instance, the bard could have benefitted from it.

You could also use it as a way to hack together a decent non-magical leader with some fighter levels. But I agree with you, better support for a non-magical leader would be very helpful. I really wish the bard wasn’t a full caster and instead was a half caster with more thematic abilities.

You’re completely right, though I think some of the smite spells specifcally would work with most of the other martial/magic combo classes, but I wouldn’t bring the whole system.

The mechanics are fully in support of the theme. Smite is a good example of something that makes great sense for the paladin – and is a fantastic expression of magical/martial hybridization – but falls apart a little when you remove it from the paladin, because of the theme getting divorced from it.

And the subclasses offer a wider range of mechanical and thematic directions than other classes’ cubclasses.

Also, the paladin comes closer than any other class – before taking subclass into account – to fully supporting party roles as defender, striker, or leader. That’s pretty neat to see.

Paladin is probabaly the most well rounded class in 5e as a whole, thematically and mechanically. The smite system is a wonderful magic-melee implementation.