Hi Vanir, your are making several good ideas. I'm getting inspired.
I'm glad you agree with Davik's presence and influence idea.
I definitely agree Davik should have a major influence in the middle city, the love child between a major trade union and the mafia. Protection rackets, gambling and vice should all be under his belt there. The swoop gang (not the Beks but the other one) could act as his standover thugs, they are less likely to attract the interest of security forces than bounty hunters openly bullying people.
I think this is wrong, as the Black Vulkars gang is not only against the Hidden Beks, but also the Exchange, as you can hear in several diallogues that they are even robbing to the Exchange guys. Do you remember the confrontation between Vulkar thugs and Exchange mobs? They were going to assault them until Canderous made his first introduction and they fleed the scene.
I think this is the opportunity to create a new gang. Hidden Beks and Black Vulkars are always related to the Lower Levels and while they are on a war with each other, I think they are more focused in controlling their own territories down there than in Middle City.
Ideas for that new gang must see which afiliation would it have (Exchange/Vulakrs/Beks/Sith....), or none of them, or all of them. You can think on using Hutt clans, or the Sith having controlled the local business in the Middle City, or do not complicate things too much and making the area all part of the Exchange.
To link things with the main plot, we could see the efforts of Davik to obtain the required permission for landing off Taris, maybe in a meeting with some rogue Sith officer or the Sith Governor (
http://starwars.wikia.com/wiki/Sith_Governor) himself, so we can put more importance in these two prominent characters in Tarisian society.
I think again, Davik's quarters could be located here.
Also, as player you could be employed by the Exchange or against them. One quest could involve capturing the Ebon Hawk former pilot Hudrow (
http://starwars.wikia.com/wiki/Hudrow), who we will find later in Davik's prison, due some spice stealing problem. Also, we could see how the Sith or the Exchange locates the fugitive duro you helped before in the Upper Level (if you helped him) the first time you go out the apartment as you will find him later captive in the Sith base. We can be witness of this or maybe help this to happen.
Wookiee slaves could be an important part of the area, as we can see Zaalbar's reaction to this, and make a connection with Kashyyyk's Czerka/Chuundar situation. Slavering could be offered to the Sith by the Exchange, and the wookiee hunters could be gamorreans or trandoshans working for Czerka.
About the Jedi idea, it could work, but he has to be hunted by Sith and bounty hunters (maybe a Canderous or Calo intervention). I agree that the old Jedi Temple should not be in Middle City and the idea of the Sith base being constructed over the Temple's ruins is good. Maybe the Jedi escaped the Sith base.
Also you can create some quest about some Republic soldiers surviving the crash and hidding with the population, or rescuing them from Exchange thugs. Maybe you could help the soldiers rescued by Zelka Forn in the medical center on the Upper City to hide in the less controlled Middle City.
You'd probably see an occasional Sith patrol, but not the regular ones and twos of the upper city, these would be less frequent and in squad siz(4-6 troopers and a Sith officer). You wouldn't have a Sith guard at the flea market for example, but you might have a troop response to a brawl there if it continued more than a few minutes.
I think that maybe here Sith patrols are disguised as civilians to keep an eye to what's happening without alerting anybody and working more as spy than patrols.
It might even be an idea to expand on a "the Sith are always watching" sort of thing, with remote cameras stationed throughout the middle city and rumours of eyes and ears for the Sith being everywhere.
Yeah, this could be great, but why they don't do that in the Upper Level? Maybe the Sith could get suspicious of you as you are going to every level, beating the duels and the swoop races, claiming bounties and more things, so, they could try to detain you as they know everything you have done, and you have to eliminate those Sith or spies before they warn the command base.