does each guild let you be the leader?

AFAIK, yes.

I have a merc who is a battle mage, and I use a little magic when I go one handed (resto/flame)

Not sure when I will do Mage q

My merc is a battle-mage as well, well he's a Nord, but I am a High Elf Mage, so I really benefited from these quests.
I just arrived at the Dark Brotherhood HQ tonight, and tomorrow when I get home i'll really get myself into the whole quest-line.

Not all wifes will follow you. Not all will even go to your house if you tell them...I've waiting like 10 ingame days when I told my wife to go to my house in Solitude and she still hasn't got there.

did u check all ur houses?

btw marriage = lols:

“So I had owned a house in the city of Whiterun, and asked her, ‘OK we should live there.’ I went there, and she hadn’t arrived yet, so I decided to wait – I slept.” As he woke he noticed someone else in the house with him and his wife, her secret admirer had just walked out of the bedroom with her.

“It’s my wedding night, guy walks out of the bedroom!”

LOL.

How do you wife someone btw?

Travel to the town of Riften.
Find and enter the “Bee and Barb” inn.
Speak to an NPC named Maramal about the Cult of Mara.
Buy the Amulet of Mara off Maramal - 200 gold.
While wearing the amulet you have new speech options to court NPCs who can be courted.
Maramal will be at the Temple of Mara for the rest of the game.
After purposing to an NPC, talk to Maramal at the Temple of Mara and you become married.
Side note: Marriage can be heterosexual or homosexual.

Godly.

Thanks

What are the pros and cons of being married?

pros:

Once married you can move into that NPC’s house or your own.
If that NPC has a shop you receive 100 GP a day and some NPCs will start a store upon marriage.
Once a day your spouse can cook a meal that increases regeneration of magicka, health and stamina.
‘Lover's Comfort’ is a buff you receive for 8 hours after sleeping in a house with your spouse. This gives you 15% increase to skill learning.
Anyone you marry can become a follower if they weren’t before.

cons:

pretty sure they can cheat on you and wont be afraid to show you haha