I will try to play a character using only major skills. I thought it would be intersting to do so for someone else.
What I've simply done is modifying these two GMSTs: fMinorSkillBonus and fMiscSkillBonus raising them to 10000. This way minor and miscelloneus skills will probably never raise ( maybe 1 point every ten years!).

I found it interesting, this way each class becomes truly unique (or at least most of them) and, for example, playing a healer you will have to rely only on alteration spells to defend yourself.
That said, I saw that the skills that never appear among major ones are armorer and spear but you may always create a custom class to solve this problem.

To balance the fact that you have less skills to raise I have diminished the fMajorSkill value a little (from 0.75 to 0.60, as you could guess raising these values will make skills go faster and viceversa). Besides an uncapper mod would be really usefull.