As a male Nord (not a Dovahkiin), I would live in Riften as the Guildmaster of the Thieves Guild after I helped the Empire win the civil war against Ulfric. Also, even though I am part of the Dark Brotherhood in the game, I would not join it if I actually lived in Skyrim because of my pesky conscience
.
I would live in Riftweald Manor with Brynjolf, my husband with the hot Scottish accent. My first initiative would be to stop all thieves affiliated with the Guild from stealing in Riften. Without the Thieve's Guild constant larceny in Riften, conditions would slowly grow better. To further speed up the process, I would use a sizable percentage of all profits to distribute wealth around the city. This would increase people's favor of me and would make Riften a thriving city. I would win over any unsure members of the Guild (or Maven) with the Amulet of Articulation.
Any thieves of the Guild caught stealing in Riften would be immediately kicked out of the Guild. In addition, all information on those caught would be distributed to the guards and Maven (now a Jarl). The guards would be commanded to arrest the thieves on sight.
I would venture around Skyrim with Brynjolf in my spare time, establishing the Thieves Guild further, even beyond Windhelm, Whiterun, Solitude, and Markath. The profit gained from the new chapters would make up for any profit lost from the ban on theft in Riften. Vex and Delvin would preside over the Riften Guild (which would become the Skyrim Thieve's Guild Headquarters) in my absence.
As Maven grew older (it would have to happen) I would slowly start to gain more of her trust, and I would take over Black-Briar Meadery. This would be easy, as I would already have her trust as the Guild Master. Also, she only has a husband and two children.
Hemming, her son, doesn't have nearly the pull Maven does. In addition, as her son, that would make him he considerably older than Sibbi and Ingun, his children and her grandchildren. This would shoot down any hope of him becoming head of the meadery. As far as being a Jarl, the throne is passed down in the family, usually. However, a good chunk of Maven's actual influence stem from her connections and her business, though the position of Jarl does help. As Hemming is both relatively old and powerless on his own, with no connections and no fortune, Maven would most likely deem him unfit for both the head of the business and the position of Jarl.
Sibbi, her grandson, is, as even Maven herself admits, spoiled rotten and immature, unfit to serve as Jarl or head of the meadery.
Ingun, the only Black-Briar other than Maven to have any sense of responsibility, is uninterested in and even dislikes her family's line of business.
With no one in the Black-Briar family able/willing to lead as Jarl or as head to the meadery, Maven would likely transfer both positions to me (especially as Jarl because of the support of I would have from the people of Riften in addition to holding the rank of Legate in the Imperial Legion).
After moving into Mistveil Keep with Brynjolf (and buying Ingun an alchemy shop because I think she deserves it), I would then appoint Hadvar (great friend and person
) as my bodyguard,
(SPOILER) Karliah
(SPOILER) as my steward, and Enthir as my court mage. I might appoint Dirge as my bodyguard if it turned out that Hadvar wouldn't be able to keep me being Guild Master
(SPOILER) or a Nightingale(SPOILER) a secret.
I will be a fair Jarl, keeping all skooma trade and crime out, winning the support of the people even more, and expanding Riften's walls.
While this is happening, the conditions of the other cities of Skyrim will be decreasing due to rampant thievery while the money from said thievery improves the city of Riften. Also, more tourism would be in Riften, helping the economy, and more thieves would be attracted to the rich city, leading to more opportunities for recruitment. Elisif or the then-High King/Queen of Skyrim would probably die in the next 5-10 years while Riften would continue to boom and prosper.
I would then most likely be elected High King due to being both a war hero and Jarl of the most prosperous city in Skyrim.
As High King, and probably in my late 40's or early 50's at that time, I would live in leisure for the rest of my days, continuing to manage Skyrim, Riften and the Thieves Guild.