I always have a hard time making a viable thief character for a few reasons: They end up getting killed in inevitable combat situations and it makes me sad, I always want to take too many perks, and I have a hard time roleplaying the motivation behind the character (Is this character just trying to make money? What's the point?)

First of all I eventually want this character to be good at fighting with bow and sword and have good armor rating. Also, I want to take most of the pickpocket perks. And I want to add something the normal thief doesn't have but I think would be the perfect skill for a thief: alteration. So my ultimate thief would end up having a perk spread like this:

http://skyrimcalculator.com/build/401192/ultimate-thief?sr=1

But I probably won't get that far. So my idea is to start off with a very weak character who spends a lot of time pickpocketing and ending up in jails. But when my combat skills become proficent, the character begins to evolve into someone who is quite agile, acrobatic and can take on any combat situation. At this point, I would probably be bored with pickpocket and have no use for that, so I would use the legendary function to put perks in other skills.

I want this to fit the character's story though. So any suggestions would be aprreciated. Tell me about your thief characters and how do you roleplay them. The "just want to make money" motivation gets old fast.

My Thief character like screwing with people who deserve. I would say he is essetially a "chaotic good" character. He is generally a nice person, but has no issues in stealing from someone if he thinks they deserve it. He joined the thieves guild only because he read the old stories about them rebelling against the arrogant rich in cyrodil, etc (As in he heard the stories of the oblivion Thieves guild). After that, he started helping them only to try and change them from the inside.

He generally only pickpocketed sleeping characters until a higher level.

Also, he DOES like shiny things too.....................

In combat, he duel-wields shortswords and abuses the speed he has from wearing light armor to dodge attacks.

At higher pickpocket and sneak levels, you can reverse pickpocket poisons and kill people or pickpocket a Forsworn Briarhearts heart and kill them....this kind of blends thief and assassin though but it's a fun thing to play around with.

But don't you end up needing some ridiculously powerful poison potions to actually kill anyone that way?