1 - Do you mean rockwool inside of hydroton inside of netpot? Ive been told to use Rapid Rooters instead of RW. You shouldnt put them into DWC until you see some roots coming out of your RW plug.

2 - I used 1/4 strength nutes for the first week and started slowly adding more nutes according to plant responses.

3 - You should get a PPM meter. I take the plants out of the water and add nutes then PH correct solution then return the roots. The PPM meter makes it easier to measure the amount of nutes in your solution. Always PH after you add nutes because nutes can change PH.

4 - Possible but not the best idea. Plants at different stages require different nutes and different strengths. Nute level for a budding plant is high and would fry a small young one. Dont really want to germinate in your DWC setup. Should use a dome or something to hold the rockwool plug until its big enough to show roots. Then introduce it into your system.

First two weeks... Hmm... biggest things for me were keeping a schedule and making sure the PH is right. Being lazy or forgetting about PH can damage and even kill plants. Hydro is much more needy than soil and neglecting your PH can cause you headaches. Also dont forget to change your res regularly. Hope I didnt forget anything. Goodluck!