Mostly liked it, but two things bothered me (spoilers)

1. I thought so too, but then I realized he's going to different countries and no one would be able to catch on unless he was going back to the same airport.

2. He did have a "no sympathy" rule which is probably why he killed everyone. However, I don't know why he let the last one live.

Those comparition are unfair, those movies are fictional more comic book type, this movie (even when is a comic book adaptation) has a more "realistic" approach.

John Wick and Bullet train has nothing to do with the killer they are in diferent leagues, a more fair comparisson would be Collateral or even Ronin another great Thriller

That being said

1, that is pretty silly is pretty lame when movies go against their own logic just for an easy joke

2, He go against all the people involve, they almost kill his girlfriend, the handler put everything on motion and the other two excuted the plan, has perfect sense he go against everybody.

I think the movie has another real problem and is that he never called his grilfriend to prevent her, that really bother me, and wasent necessary from a narrative perspective because he could call her she runs the bad guys go to the house dont find her and burn the place, our protagonist knows he is in danger and go against them, and we still have our movie but I think he made this msitake because the director want to give us something to empathize more with the character and make look his motivation less selfish, for that reason he gives us this girl almost desfigured, and now we can see more humanity in him and we are more confortable falling him and supporting him in his revenge.

1. He travelled a lot abroad, where almost no one knows what those aliases mean.
2. He killed his middleman to find out who was sent to kill him ( the 2 subcontractors). He died to fast though . The secretary could identify him so she had to go too. The brute and the q tip were sent to kill him. They were trying to find out where he is so they tortured his girlfriend. When he killed them both it wasn't ( only) revenge, they were paid professionals that had a job: to kill him. So they had to go too. The millionaire could easily hire other hitmen to try and kill him, but he preferred to "reason" with him as he's very rich and well known so his death would definitely be followed by a thorough investigation. The killer himself said: the police's effort increases proportionally to the victim's fortune. Plus it looked like he wanted out, not to be on the run his entire life. Although I think he might still be...

Not killing the "client" just sets up the sequel.

For the fake names, I noticed the Sam Malone alias was for a Massachusetts license (the state where Cheers takes place). I agree that the gag was not worth it.

As for assassinating the billionaire... a camera caught his face. If he killed the guy, it would have generated international headlines and he'd be on everyone's radar. I don't think there would be any familial vengeance for killing a rich, greedy guy -- rich, greedy heirs would be relieved. So would the competition.

Given the logic of sparing the billionaire, I don't know why he killed The Expert; I'd think she would be entitled to professional courtesy. I suppose he was coming unglued. His face twitches at the end, which is probably a callback to the beginning when he missed the sniper shot. Alternatively, it could suggest he may have been poisoned in a manner he threatens against the billionaire (radioactive speck on favorite coffee mug). He did drink from her glass, and she inferred he had been worried about poison. The Expert also warned that when his time comes, he'd be thinking of her.

The Killer should have alerted his significant other that the job went sideways and she should get to their safe house. I don't know how she survived.

As a European, most of the fictional names were lost on me. I looked them up afterwards and should have caught more of them than I did. For example, I said 'Ah, of course' at Archie Bunker, because I knew in the back of my mind that Bunker was the American remake version of the British Alf Garnett, but only as the answer to a trivia question. Never seen that show.

Never seen The Partridge Family, The Bob Newhart Show, All in the Family, The Mary Tyler Moore Show... &c. Have seen The Odd Couple (the film, not the show) but it was a long time ago and I wouldn't have remembered those character names. They're just Jack Lemmon and Walter Matthau in my mind.

So, yeah, I think an American could travel around abroad using those names without raising an eyebrow... with the possible exception of Sam Malone. But he does seem to use a lot of them in the USA, so your point in a valid one.
.

The whole point of the movie was that he was breaking his rules. I thought that was one part of the bear story. Taking things personally and not being dispassionate.

“ Everyone else played their part in the industry that is his chosen profession”

The client too.