is bruiser fizz still a thing?

Honestly dude, It won't matter what champ/build you play at any ELO if you are good enough at it. Play what you have fun with and you'll find yourself winning more often

Tank Fizz is strong atm, with the Grasp keystone. Try it out.

It has good midgame and kind of weak laning before lvl 6. Lategame tank Fizz can kill only very squishy targets.

As a jungler he can. He is pretty weak in the jungle early on, but once you start to get items and hopefully snowball you will be in a good position. You basically build him like Jax. Play him like Jax. Except he is a bit better because he has more reliable cc and is a lot more slippery.

Not really.

Fizz is a pretty dirty Rageblade abuser. You can easily just go Rageblade->Wit's End->Full tank and kill bitches.

Yes, but there are some conditions to it. I just had a guy play it in one of my low Plat games and it worked terrifyingly well.

There are some draw backs though:

1. Bruiser Fizz with Cinderhulk is not as strong. Cinderhulk clears far too slowly to compete with the other upgrades. Most tanks take Runic Echoes now so they can actually get through their jungle and get better damage early.

2. These is no point in going Runic Echoes Fizz. You might as well play him mid lane.

3. Devourer Fizz works, but Xin, Jax, Yi, Shvyana, Warwick, and even Udyr works better with devourer.

Out of the 3 options, I've only seen Cinderhulk Fizz around my ELO. These players compensate their lack of income from the jungle by repeatedly ganking lanes and tower diving with Fizz's BS troll pole to force the enemy jungler to stop farming as well and counter gank. You shouldn't have to worry about it unless the Fizz player is experienced with this playstyle.

With devourer & rageblade, yes.