Scale-Is-Pale: "And so I will trade you this beautiful-"
Guild Member: "What?"
Scale-Is-Pale: "Hmm?...What is it?"
It is known that Argonians excel in most of the core skills that make an excellent thief. However there is one stealth-related skill of which they fall short. The art of speech and bartering.
Scale-Is-Pale (He is a very pale Argonian indeed) acted as an independent thief for most of his life in Cyrodiil. He would rob houses, chapels, mage and fighters guilds. However he would find it excruciatingly frustrating when a long night of thievery would often be rewarded by mere pennies. Barely enough for a decent meal! Such was his speech lacking that even the more dodgy merchants were reluctant to dish out their coin for his goods. He knew that if he truly wanted to profit he would have to, one way or another, force himself to become a true master of mercantile.
For hours upon hours, night after night, sometimes even foregoing sleep, the Argonian would face his own reflection, hunched over the waters of the Niben Bay on the shore. Then he would proceed to haggle with it... hand motions and all. He would offer this deal or that deal, pick up a rock in his hands pretending it was a precious gem. Over time he would be come to known as 'Touched-In-The-Head' by passers by and the people of Bravil.
His odd training method however did pay off. He did and does to this day, get the BEST deals with living breathing merchants. His near-mastery of the art of trading over a span of close to two months was truly an astonishing feat. Although it did come at a price. Every now and then, mostly when alone and all to himself, Scale-Is-Pale will talk and haggle... with himself. It's as if he enters a trance, unaware that he himself is even doing this. This occurs at random though luckily in the presence of people it comes out more as mumbling but still audible.
He eventually travels to Skyrim to try his luck at thieving there and decides to join the Thieves Guild. It is in Skyrim where he first meets The Mad God Sheogorath face to face. Scale-Is-Pale instantly took a liking to him. Felt drawn to him even and to this day worships his Lord. The Argonian carries the Wabbajack with him everywhere, using it whenever he pleases. On the bandit charging towards him or the sleeping old lady in a house he's been sent to sweep.
This marks the end of the origin tale of Scale-Is-Pale.
Or rather, Touched-In-The-Head, if you hail from Bravil.
Lockpicking - Maxed out. Just for role playing reasons. I like to think of this character as a legend with a lockpick.
Sneak - All perks EXCEPT Assassin's Blade, Silence, Shadow Warrior.
Speech - The bartering side (left branch) of the tree up to Fence. First haggling perk maxed out. I don't think Master Trader is necessary but you can take it if you want to.
Archery - All perks except Critical Shot, Bullseye, Hunter's Discipline, and Ranger.
Light Armor - Agile Defender maxed and custom fit. As a thief you should rarely be taking heavy punishment.
Smithing - Steel Smithing and Arcane Smithing. I chose Dwarven Smithing too for my version of the character as I like dwarven bows. But you can choose elven if you prefer. I merely took this skill to improve my bows and give them an extra edge damage-wise.
In terms of armor I primarily wear thieves guild gear and eventually the guildmaster armor. I'll mix out a certain armor pieces here and there for pre-enchanted pieces that improve skills I do use such as gloves that boost archery over gloves that boost lockpicking (this lizard is already a badass with a lockpick).
Standing Stone - The Thief for a large portion of the playthrough. After maxing your stealth skills the choice is yours.
You'll be a rich lizard. And paying for training in general should be no problem at all.
Other races do work for this build as well. Those known to be poor in Speechcraft such as Orcs for instance.
On a final note, there is a part of the thieves guild storyline involving The Daedric Prince Nocturnal and having to become a Nightingale. However it's nothing that you can't roleplay out of. For example you could say your character is just faking worshipping her for the benefits OR, being quite touched in the noggin' that they agree to be a Nightingale just for the fun of it. Besides, I'm pretty sure Sheogorath already has first dibs on your soul the moment you lost the plot. It's also expected that you complete Sheogorath's quest we'll before completing the Thieves Guild so other way, roleplay-wise, you're fine.
Hope you enjoy this build guys