1. depends on how you are doing them, like what set up youre doing... if you do a rubbermaid set up you can get 2-3 plants with 6 bulbs... if you do a bath tub you need 3 cfls per plant or so id guess... so 10-12... for 6-8 you might want to to consider 3 plants
2. takes usually an extra 1 to 2 weeks longer then they state when you buy the strain... if it states 7 weeks of flowering, then you'll need 9... however youre not vegging so you gain time doing that
3. yes you can get that easy, look around the site to get an idea of how people yeild... ive seen guys get an oz. off one plant with 4 lights, so im guessing you can get 1.5-2 if this is your first time with 4 plants... tons of people disagree but it seems to flip both ways... if you do it properly then you shouldn't have problems... and it totally depends on the strain as well