1) Yes, incubation is possible, but difficult. Sometimes I use this technique to get lucid. I incubate a dream where I am in a room with RC written on the wall all over like something out of The Shining. All work and no play make ninja a dull boy.

2) Every night, actually 3-5 times a night

3) Lay in bed very still with your eyes closed when you first wake up. It'll kick the dreaming part of your brain back on and bring forth your dream memory.

4) The next REM cycle will be even more vivid. The first couple are weak and short, but then afterwards they are always long.