What if Seth had chosen to go this route. Maybe in a alternate universe he was more inspired by "Aliens", "Terminator" "RoboCop" etc than Trek when coming up with the show
Plausible.
1 Captain Mercer A man recovering from a year long drug and alcohol bender after doing the whole Nick Cage thing in "Leaving Las Vegas" after finding out his wife has cheated on him with his best friend Mallory but inside of dying he is called back into duty and given command because war has broken out.
This is okay, but I think the role of Mercer would need to be re-cast in order to handle the drama. Also, because of circumstances, he's not sure of his feelings for Grayson.
2 CMDR Grayson: She tried to keep him from command by blackmailing the Admiral because she wanted to be captain but he was able to not be brought down. Instead of sending her to prison he makes her first officer because she is still one of the best military experts in the fleet.
The blackmailing is too MU-ish. So, no blackmail. In addition to her cheating with Mallory, have her lose Mercer's child in a drowning accident of something, which naturally, puts a strain on the marriage, which then leads to the affair with Mallory. Also, she's still very much in love with Mercer.
3 Mallory: Assigned to the chip even if his former friend didn't want it. He deals with a intense sexual perversion of drawling penises all over things and very anti social behavior. He gets a robotic leg in the pilot after robot Issac cuts it off as a joke. Mallory uses his robotic leg in action scenes often kicking people to bloody deaths.
Too over the top. Have Mallory lose the leg in a duty accident and have it replaced with a robotic appendage. Also, he is still in love with Grayson but also respects Mercer, at least professionally.
4Dr Finn: Abandoned her kids a few years ago to follow her dream of making big bucks as a Doctor. Takes job as CMO even if it's beneath her talents simply because she was paid a huge amount of money.
Abandon her children for money? No. Have her story be that earlier in her career she participates in a Union attempt to save a dying race which accidently speeds up their deaths. Though not her fault, Finn holds herself responsible for genocide and is wracked with guilt and shame. She is on Orville, which is not a demotion, but is not nearly the level she should be on. She still loves and cherishes her kids who are the only thing holding her together. More like Doc Cottle than Beverly Crusher.
5 Bortus: Killed his husband when his husband didn't want their baby to have gender alteration surgery. Nobody knows, except the viewers that he is a murderer. Bortus is friendly around people but when he is alone you can see that he has some Dexter Morgan tendencies that he hides from the crew.
Again, too MU-ish. Have Bortus on Orville with his husband illegally (per Bortus' people's law) raising their little girl. Make Bortus' people more sinister and high profile. They suspect Bortus and hubby of some shenanigans with their child but need to prove it. His people believe that women are so inferior that they should all be erased from existence, but they know this is impossible. So they hide their prejudice.
6 Alara: Takes a alien version of steroids to maintain super strength like others on her planet though she was born without it, which happens from time to time with people of her species. Because of the drugs she has intense mood swings.
No, Alara's strength is natural, but she is more troubled by her parents treatment and acts out in different ways. My understanding is that she is only stronger while on planets with less gravity.
7 LaMarr: Child prodigy who flamed out at a young age and has chosen the life of being a ordinary pilot. Very shy around people and doesn't know how to connect with them. I am thinking William H Macy in "Magnolia."
This, I like.
8 Issac: A robot from a robotic race that is the shows main villians and who they are at war with. Issac was abducted and re-programed to serve the ship. He has no free will and is treated like a tool.
I like this, except I might make Isaac and his people exist only digitally. But if they do have bodies, make them look more ironic, like the Cybermen on Doctor Who and less like Robbie the Robot on Lost in Space.
9 Yaphit: The the movie blob he devours lifeforms to eat. You will see him constantly absorbing cats,dogs,monkeys etc or whatever he can to eat. He is afraid to be around the Doctor because he is married but has feelings for as well.
I think it's hard to do a good drama with this character. I would eliminate him.