1. The 6"blocks will work just fine . I use them all the time .
2. You can grow 6 to 9 plants in a 3x3 tray . The more elbow room , the better . With a 7 foot height limit to work with , more shorter plants will give best results .
3. Using a trellis depends on your grow area . I like them but I...
Lucky ( Unlucky ) , This is a grow site . Not a hook up site . Grow your own shit . You sound like a cop or some dumbass trying to get someone in trouble . Fuck off !!
Go back to the East coast . We don't need you in Colorado
I grow on a smaller scale . I use 2 x 4 trays . I grow up to 6 plants at a time . I use 6x6 rockwool blocks from start to finish . Sometimes I stack a 4x4 cube on top of the 6x6 cubes . I flood three times a day . I never use hydroton as it is hard to clean between grows and adds to cost ...
you can find an answer on you-tube much faster and probably a video too .
Do a little research on your own instead of asking questions . educate yourself .