(A slight flash warning for the video abose since it has some glitch effects)

These were some doodles I did just to get a sense of everyone's roles (or most of the roles since I didn't want to go through every individual character)
If I'm being honest the designs could always change depending on my impulses and whether i think it'll be more fitting or not.

Since thinking about the different possibilities of the swap au was too troublesome I went with the most popular choice (no one's fitting the roles perfectly)
The hotel is run by Adam (the first man and first sinner) and his cofounder Lute (former angel exterminator).  Adam found Lute during extermination day and helped saved her.  Lute is fully aware of who Adam is, but Adam doesn't know who Lute is.
The first resident brought to the hotel was Valentino, a pimp porn star who is under Angel Dust's contract. He would often cope with his suffering by smoking and drinking.  Occasionally, Velvette would come by to visit Valentino.  The two have a clashing friendship where they'd often argue but they do enjoy each other's companies, especially when shopping.  She doesn't believe in the redemption but sometimes comes by to help with the marketing.
Vox, the infamous TV demon who has gone missing for 7 years after barely surviving a fight with Alastor, has returned to help the hotel seemingly after the disastrous commercial was aired.  His technology was still prominent in hell must to Alastor's distaste (especially since his assistants can just work on upgrading his technology when he's away).  He seems to be already familiar with Valentino (He has also taken Husk's role because it was hard to figure out who husk would swap roles with).  He would sometimes summon his contractor Mimzy to clean up the place. Niffty is someone Vox became very familiar with (whether it was by choice or not is another question), who is very drawn to Valentino and Vox for being bad boys.  Vox has a very notable obsession with Alastor that Lilith often takes advantage of to fuck with him for funsies.
Lilith is the Queen of Hell and deeply cared about her role as a ruler, which unfortunately caused it to fall apart and become estranged.  She has not seen her daughter since she was a child, and only has pictures of when everyone was still together.  Through the grapevines she has heard about the hotel Adam was running.  While redemption for sinners was a foolish idea, it isn't impossible, plus it can go against her husband's idea that it's impossible to redeem sinners.  She has a complicated past with Adam (former lover and such), so Adam was very unwilling to accept her help but eventually gave in.
The overlords of Hell which rivals the hotel are Alastor, Angel, Husk.
Alastor the radio demon is incredibly frustrated that he failed to kill Vox, and will never let the humiliation stay down.
Angel is upset Valentino moved out of the hotel for some stupid redemption bullshit everyone knows isn't going to work.  He'd also be having less control over Valentino with him further away. He's taken over Val's role in the pornography industry
Husk is the gambling demon, who's made plenty fall from fortune, and often someone that would often be called by Alastor to stabilize and calm down Angel.  Despite having the most life experience, he is the youngest demon among the three.  He is also the one keeping the group together since Angel and Alastor don't exactly get along too well.
Cherri is someone that would amplify the worst of Angel and his emotions, a catalyst for destruction and cause for destruction, but hey the two are having fun.
Within Heaven contains: Lucifer, Charlie, Vaggie, Sera, Emily
Lucifer is an angel of high position, who deeply cares about Charlie. He has avoided being casted out of Heaven, as it is only known that Lilith stole the fruit of knowledge alone and shared it with Eve.  He tried to concentrate on the family, since they were the only ones who loved him, however it began to grow distant since Lilith would subconsciously prioritize the people over her family.  Eventually, he felt like Hell wasn't suitable to raise Charlie, so he took Charlie with him to Heaven.  He helped her blend in with the angels so they wouldn't suspect a thing.
Charlie managed to blend into the angelic crowd, and even look like an angel to those around. She is considered a wonderful role model who is kind and caring to everyone around her. It is known to little that she is the lead exterminator and that she enjoys exterminating demons. She hates demons, and believes that extermination is simply what's deserved for them.  She is aware of Lilith being her mother, and absolutely despises Lilith (possibly some severe mommy issues, and Lilith is part of the reason why she hates demons).  She has became more manipulative over the years, and knows how to get what she wants, especially since she is trusted by Emily.  She is close to Lucifer, since he's the only family she'd consider, but she never really talks about her dad publicly.
Vaggie is the right hand man and girlfriend of Charlie.  She is Charlie's greatest supporter and will do whatever she can to help Charlie, no matter what heinous acts must be taken.  She was originally conflicted on the extermination of sinners, however eventually came around to it after Charlie convinced her.  She has great combat abilities and backs up Charlie, covering any weaknesses she would have whenever they fight together.  She considers herself Charlie's protector, and would make sure nothing hurts her sun.
Emily is the high seraphim and protector of Heaven.  She was created after the Eden incident, originally made to be an angel that would help keep souls happy, however she was given the role of a protector instead.  Since she has heard about the horrors of sinners from many angels and Charlie she took up extermination as a last resort, believing it'll be the best option to keep Heaven safe.  She feels incredibly guilty for doing so, as she believes there's the best in everyone, however she believes it's for the best.  After all, sinners are in hell for a reason right?
Sera, after protesting against the condemnation of the humans (Lilith, Adam, Eve), she was to step down from her position of protecting heaven.  She is still a seraphim, however since it is believed her emotions and attachments will cloud her duty, thus the job was provided to Emily instead.  Since she has been around longer than Emily, she often helps guide her with official duties.  Since she does not have the energy to make people feel joyful, she instead uses her time to listen to the stories and sorrows of the different souls.  Sera is unaware about Emily's decision for the extermination.