I'm a little confused on how many "low skills" you need to qualify for each promotion. Do all required skills need to be at the mark, or just one or two?

Two of the skills, example long sword and blunt skill to be promoted in the Fighter's guild.

So its like Morrowind, one "high skill" and two "low skills?"

Well it's like this. Say for a promotion you need to have Longsword at level 50, and blunt skill at least at level 30. Major and minor, for two skills.