The definition of a traditional hookah is more than the multiple tube.

The way a hookah smokes up tobacco (Shisha) is by having a hot coal over the top of it. Many hookah's have only 1 tube. They also filter through water like a bong but it's really the ignition process that makes a bong a bong and a hookah a hookah. I've seen bongs that look like hookahs but have the wrong type of bowl on them for that long smoke that you get from a hookah.

I wouldn't smoke weed out of my hookah. MAYBE blend some hash into the shisha.

As for screens, Gauze I find is actually a metal screen while a glass screen (AKA Jacks or flowers) are for glass pieces. I use screens with everything because you lose a lot of smokable material into the water of a bong otherwise, plus cleaning out a bong full of ash is far worse than keeping an ashtray and a poker around.

You did miss Ash Catcher, the optional precooling chamber that separates ash from smoke by gravity for use in a bong. It replaces the slider.

And Glass Wand, the piece of glass you get glowing hot and stick into the bowl to keep the butane out.

And the waterfall is great but if it's a large piece it takes a long time to fill up and makes the smoke kinda stale by the time you get to puff.

My favorite gravity bongs are the ones that use really super-long downstems and water filter the smoke with the same water that's reducing pressure. That's brilliant to me.