Need help learning about the NFT system

OK, I get some of the system but don't get it all so if i tell you guys what i get and what I need to know maybe you could correct me where i'm going wrong if i am.

1) OK so I've heard in a 4x4 NFT table I can grow 50 plants, is this true?
2) with an NFT system all i need to do is have the table at a slight angle pump the water through 24/7 up one side and it slides down to the other and back into the reservoir, right?
3) Do I fill the actual table with clay balls and plants in rockwool or fill the table with pots with clay balls and rockwool in them?
4) I've heard 1-2 1000watt lights is enough to cover all the plants in a 4x4 NFT table system, is this true?
Can I put them in this system from seed or would I need to use plants with an established root system(clones)?

I've been looking around for a while, YouTube and Google for how the setup actually is but it's hard to find answers to these questions.
I see some great grows on YouTube with the system I want to build but he doesn't explain how it works and what I'd need to do so gets me stuck a bit.

Directly from simplyhydro.com:

"This is the kind of hydroponic system most people think of when they think about hydroponics. N.F.T. systems have a constant flow of nutrient solution so no timer required for the submersible pump. The nutrient solution is pumped into the growing tray (usually a tube) and flows over the roots of the plants, and then drains back into the reservoir.There is usually no growing medium used other than air, which saves the expense of replacing the growing medium after every crop. Normally the plant is supported in a small plastic basket with the roots dangling into the nutrient solution.
N.F.T. systems are very susceptible to power outages and pump failures. The roots dry out very rapidly when the flow of nutrient solution is interrupted."

So to answer a few of your questions " N.F.T. systems have a constant flow of nutrient solution" so it would be constantly 24/7.

Also using hydro-ton and or rock wool or anything other than a device to hold the plant wouldn't be needed. You may have smoke success with it though maybe someone who has actually done this setup can help.

Right ok, so i can run it 24/7 that's good news!
What about the other questions mate?
I have read and seen that you do need to use some sort of medium, such as clay balls, the NFT system that you describe is one where the roots sit in the reservoir but my reservoir will be far below the tray, pumping water up through a pipe to the tray, it's a slightly different.

I think that 2000w would be way too much if i am not mistaken. I heard that 3000 lumens per square foot is plenty maybe 5000 but with one 1000w HPS you'd have 9000 lumens maybe this is a good thing but there is such a thing as too much light. I think one 1000w would be good as long as you have proper cooling/ventilation.

As for fifty plants squeezed into a 4x4 area that may be a little over kill I mean divide 16 by 50 and that's how much space you'd have to work with for each plant. I would do eight max maybe that is just a personal thing. I have never done an NFT system so maybe some rules change I would assume that an NFT system is like a EBB and Flow system with more oxygen but then again I do not know all the science behind it. I do however have a 5x5x7 Box for my plants and I would definately not put 50 plants in there. I could probably cover the 5x5 area with about 8 plants depending on size/strain.

I would definitely say after reading the NFT system from the link that Jasonian posted that you would not be able to germinate in this system as well.

In a 4x4 I wouldn't go higher than 1,000

@gonenowhere thank you very much you've been great help!
oh and the 50 plants thing have a look at this mate, http://www.icmag.com/ic/showthread.php?t=237137

So I'll go for 1 1000watt light.

you guys have been great help tyvm! Sometimes all the ifo is there for you but you get yourself in a mental position where you dont think you can see it but it's all there i think this is where i was so tyvm for all your answers!

if you want a better nft/aero setup you should check stinbuddys thread, harvest a pound every three weeks. 50 plants is about 40 more than you would ever want in that area. more plants is not always better, i get around 30% more yield with my 12 site systems as i did with my 21 site systems. as for that 3000 lumen statement, i have over 13000 lumens per square foot over 36 plants. i have run nft/aeero for years and never have i run the pump all the time. this will cause a ton of heat buildup in the res. use a recycle time, i do 80secs on/8 mins off.

I'm looking at his set-up now, thank you!