Question #1:
To get a High Contrast Albino, you should use a very Dark animal to make Albino hets. With that, you breed those Hets together and get a High Contrast animal. It's selective breeding at it's finest.
To get a low Contrast Albino, use a light animal to make Hets.
Question #2: It's all in the pattern. You will have to look at pattern for those guys...
Question #3: It does matter slightly. The inclination for high whites to throw high whites and low whites to throw low whites is there, but it is not a set in stone rule. I have produced high whites with my low white male, etc...