I'm really not familiar with the old/post BBY lore, but as for Luke, the Jedi, the Force and all that. I've always hated Lucas' religious themes. Lucas describes himself as a buddhist-methodist, but his understanding of buddhism is retarded so we got a weird conception of the Force and monkhood, him being a Methodist/protestant means we also get weird ideas of abrahamism to mix into it all.
I've already talked enough of how the Lucasian idea of Yin and Yang is horribly misrepresented by the Light and Dark Sides of the Force. Suffice to say, it's got more in common with Tolkienish magic, where the mages sent by Illuvatar have good magic and Sauron's minions left over from Morgoth's army have evil magic.
As for Lucas being a Protestant, it doesn't really count outside of basic Abrahamic concepts.
The idea that the jedi should remain celibate is from catholicism, plenty of buddhist monks only do it for a while then go back to "civilian" life and marry women. Lucas just mixed a bunch of misconceptions to make a sci-fi religion and now people try to make sense of it.
The Catholic Church maintains celibacy to keep the clergy from being a drain on the Church's finances. That, and they actually had married clergy for 1000 years back when the Roman Empire supported the Church for 700 years straight. The fact that the Jedi have Republic support for 25,000 years means they should be able to pay for the Jedi having families just like any other member of the Republic military and bureaucracy.
Especially since in certain eras, like the Exar Kun War, the Jedi did have emotional attachments and married couples. Vodo-Siosk Baas had his two Cathar acolytes making out at the back of his ship, and he didn't care. When he was still a Jedi, Malak describes the push for celibacy and cutting off emotional attachments as having gained power after the Exar Kun War, but there were still Jedi arguing for love, as Malak noted that the offspring of Jedi tend to be powerful in the Force. During the Republic's Dark Ages, some Jedi who protected their subjects and became Jedi Lords had kids whom they passed their titles, land, and power to.
That really doubly applies. From Luthen's speech in S01, it would only make sense he would die a forgotten and mundane way. For most of season 2, we were shown how the Rebellion outgrew not only Luthen, but even those close to him came to distrust him. Bix, Kleya, Cassian and Mon kept critizing his methods and goals. By the end of episode 9, if Luthen died, there would be plenty enough that the rebellion would go on, he had made himself redundant but that was his goal anyway.
I think that has more to do with Luthen's methods, he only knew covert ops and backroom deals. He wasn't cut for the bickering and the officious debates going on on Yavin-4. Luthen, Mon, Organa and others all serve different purposes in the rebellion. He knew his work would outgrow him and when he had to face the wall, he did it on his own terms.
That, and the idealistic Alliance crew, from the Rebels show to the OT movies and even the SWEU, would've never tolerated a guy like Luthen who kills allies like Lonnie and Anton Kreeger just to cover his tracks and further his goals. Even if they managed to extract him from Coruscant so that he could join the wider Rebel Alliance, his methods would inevitably end with the Alliance getting rid of him. Wedge Antilles or Sabine Wren would've been ordered to kill his ass before he became a liability, especially with everything he knew, and the fact that he kept killing Rebel assets to cover his tracks. Someone like Jan Dodonna or Crix Madine wouldn't tolerate him icing an ISB agent who was a snitch for the Rebel side. Especially since many a Rebel officer began their career as an Imperial who then jumped ship.
I remember how in Rogue Squadron 1, if you kill too many friendlies, the commanding Rebel general cancels the mission and calls Luke Skywalker in to "discuss his tactics". (Read: court-martial his sorry ass.) Someone like Luthen would probably be forced to face the wall, even by the Rebels, given how he's got no problem killing friendlies for his own ends.
For TIM in ME, it's similar. TIM will never be thanked for saving Shepard, for funding and aiding so many efforts against the Reapers but he was still extremely instrumental in saving the galaxy.
That is the point; that is why I made that analogy. TIM will go down in history as a hated man, but it was his effort that saved Shepard, who then went on to save the galaxy from the Reapers. TIM is still a ruthless son of a bitch who has no problems killing allies and innocent people to cover his tracks and achieve his goals.