So it actually sounds with this, that if I wanted to leave it at the default settings, I could choose majors that are my weaker skills so I don't have to use as many skill points to increase them?
This doesn't make much sense. Of course you should choose the skills that you need as majors or you won't be able to level up quickly in them. If you pick the useless or weak skills as major skills you can level up quickly in these skills, but what's the point if your most used skills eat all the points on level up because they're so expensive?
That is actually one of the things I love about Oblivion XP - specialization and major skills matter a lot because it is very hard to bring a minor, non-specialized skill to a decent skill level unless you want to waste all your points on it.
If you like to be a Jack of all Trades be warned though. With default settings you will never be able to bring all your skills to 100, not even closely. Another thing I love about it. You have to choose in which direction you want your character to progress. Unlike in vanilla, where it doesn't matter and a character that started as a plain warrior class will be a masterthief-archmage-superwarrior at level 30.