Any worth it?

I might say that Nidoking and Slowbro worth the dust but after the last cp changes they are way worse.

You can power up the Vaporeon and stick it in a gym/use it as a general attacker. It's at a decent enough CP already but could easily go 2k+

I'd also keep the Psyduck. If it is at 1.5k CP, it should evolve into a 4K Golduck.

I'd power up the vaporeon and use for gym defense. maybe the slowbro if you can find a weak gym to defend.

I would power up the Slowbro it has great IVs and a good defensive moveset, making it hard to find a good attacker that isn't week to one if not both of its moves. Unfortunately with the nerf he will probably be around the middle to lower end of a gym butt he will help with gym diversity.

Golem it already has decent cp and a good moveset I would just use him as a niche defender and save candy and dust for a better one.

Nidoking I would maybe power him up just a little depending on the cp of the pokemon around you and use him to fight fairies.

Golduck I would use as a prestiger

Vaporean is tough you will probably get a better one butt its decent so use your own discretion.

In my opinion none of them need or are worth powering up, if you only want the best Pokemon. Otherwise it's just your own preference what you think looks cool to put in gyms or to use on attack.

The Vaporeon is worth powering up if you're not anal about IVs, but if you're using it for attacking, it doesn't need powering up.

Even though it's "worth" powering up on defence, that doesn't mean you have to. I'd rather just evolve a high level Eevee regardless of IVs and save myself stardust from having to take that Vaporeon to 30. Eevee candies aren't an issue in my case, so I'd rather spend more candies than dust.

Against defending Rhydons who are basically the new Arcanine (high CP Vaporeon fodder), Aqua Tail is fast enough to use in between it's quick moves and still dodge, so it's actually better than Hydro Pump if you dodge. But like I said, it doesn't need powering up on offense.

Slowbro with that moveset is good against grass types, especially grass/poison because of Confusion, although I'm not sure if people even use them anymore. I personally use Jolteons for water types now since they'll do a quicker job than the grasses. So if people aren't using grasses as much in your area, your Slowbro becomes less useful, but still usable.

Golduck with WG/HP is basically a worse Vaporeon. If your favourite Pokemon is Golduck and you don't care that it's completely outclassed, it's your dust to spend, not mine.

Golem and Nidoking don't have any realistic niche uses right now - RT/SE is probably the best counter to Charizard, although you don't have that moveset and how often do you see Charizards - But if you like using those Pokemon, who are we to say you can't power them up. If you only want the best though, they aren't it.