My setup + a few questions (pics)

This is my first DWC setup.
I build it myself from things I could find locally.
There are 5 plants growing in there, I don't know what strains they are but just by looking at them I can tell they are all different types.
The nutes used are GH Flora, at 5ml from each bottle (3) per gallon.
I check the PH every day and keep it at 5.8
Temps are 75F with lights on and 65F with lights off.
My lights are two floro shop lights tied together at an angle and total 128 watts. I'm only gonna be using the floros for vegging to save some power. When I decide to flower them I will be using a 600 watt HPS.

How does everything sound to you guys so far? Any suggestions? Ignore the seriously messed up leaves on some of the plans, that was nute burn from the previous nutes I was using.

Now I have a few questions for the pros out there:
These babys are getting pretty damn stinky. I know I can get one of those air scrubbers but how exactly do they work. Obviously I need a fan to run air through it but do I need to run the "exhaust" out of the room? Or can I just recycle the air within my grow room?

My other question is about the lighting. I keep my lights right on top of the canopy so I can get as much lumens as possible. Does the height of the light affect the shape of the plant in any way? I know a guy that had his light way up high and his plants reached for the sky and turned out to be really tall and skinny. Mine are short and bushy and the stems are massively thick for their height IMO. Is this a way of regulating how tall my plants grow? In other words, if I don't raise the lights at all will the plants start to spread out rather than grow upwards?

Thanks in advance!

How close are the lights? it dosnt really seem like a problem, and as for the air extraction question, Its better to extract it because poor air, poor plants.

Here's another one with how low I keep my lights

Keep your tubes about 2in from your plants. Yes, keeping your lights close will help your stems grow thicker and your plant will be much stronger in general. You may want to pick up a couple Compact Fluorescents (CFL) for when your plants get to be to tall for the tubes to take care of. CFL's are great for support/veg light, and they're 7-9$ so pretty cheap. Good luck, it looks like your on the right path so far.

Hey thanks for the advice.
Ive been thinking about getting two more of those shop lights and with a drill, some screws and maybe a few metal brackets I can make a huge reflector unit composed of the four shop lights (256 watts). It would be built in such a way that when lowered on the plants it would surround most of the canopy and supply light from all sides. That would be some pretty effective lighting without killing my power bill. When its time to flower, well thats a different story hehe.
I'm soon ordering a 600 watt HPS light. I'm not really that paranoid but is there any risk with ordering off ebay? HTG supply to be exact.

I made two more DWC systems, 5 plants each. I'm thinking about doing 12/12 from seed on this first grow. Other than getting smaller yields, is there anything wrong with that? I'm also planning on making a carbon scrubber soon because my room is starting to smell pretty bad and thats just from 5 plants. Is a carbon scrubber effective? Are there any other (cheap) ways of getting rid of odors?