1) Will using staffs raise my destruction skill?

2) Will I need to sink points into magicka to be able to summon master the best summons?

3) Will I be able to get all the perks I want in 1 hand, archery, conjuration, sneak, light armor, enchant, and alchemy?

I started a new character already that is a mage, and although I am having a lot of with him, after reading about how weak destruction is, I am going to start over a new guy so I am not relying solely on conjuration at higher levels. I am level 15 now. I want to do an assasin / thief / conjurer character.