1- the focus of the beam is smaller because of the blue laser and higher numerical aperture. I guess they normalise it to either the CD or DVD.
2- A prisme is a triangular piece of glass where light is refracted ('gebogen') when passing through it.. A mirror reflects light.
3- Not sure.
4- It's a measure for the strength of the lense combined with the index of refraction of the medium.
http://glossary.its.bldrdoc.gov/fs-1...-025/_3615.htm
5- I think pit is used for for Read Only. It's a little hole. Mark is used for Rewritable, it's a amorphous 'mark' in a crystalline surrounding. Track pitch is how close the different tracks are to eachother.