Dick doesn’t kill in the show though, he’s just extremely (like… REALLY) violent and can’t control himself when he puts on the mask. Starfire killed twice already I think and that’s fine coming from her, it’s obvious it’s something that will be a character arc for her and Dick to help them get closer.
From what I read he’s heavily based on the Perez/Wolfman era that had 4 years of story. Dick had anger towards Batman and tried to find his identity, just like in the show but with different reasons. Here’s someone who read it explaining Dick in the show.
There have been a few different versions of this period of his life in the comics. This show is based on the Wolfman/Perez era, which I think is the best version because it unfolded over nearly four years of stories, allowing for a lot of nuance and detail that made it easy to understand all the forces at work.
Dick joined that iteration of the team during his college years. Going to school, working with Batman, leading the Titans, maintaining a solo career, and working at Haly’s Circus all at the same time ran him ragged. He had high expectations as a student and took his commitments to Bruce, the Titans, and Haly’s very seriously. So there was a period where he was really out of sorts and overworked, pushing himself relentlessly.
It would be revealed later that this was compounded by the lingering effects of torture he suffered at the hands of Brother Blood. It all came to a head and he decided to stop being Robin. He spent a short time with no superhero identity, but was forced back into the fold during The Judas Contract. That’s when he became Nightwing.
This was changed a couple years later during a continuity upheaval at DC (Wolfman & Perez’s Crisis on Infinite Earths). In the after math of that, they chose to change Jason Todd from being a contrived copy of Dick Grayson (Jason was originally an orphaned circus kid just like Dick) to an angsty street kid with an attitude.
In that version of the story, they threw out the detailed Titans version and replaced it with this: Dick was shot by The Joker, which scared Bruce and caused him to basically fire Dick, forbidding him from being Robin. Dick became Nightwing and Bruce almost immediately ran into Jason (stealing the wheels off the Batmobile) and made him Robin. It was pretty ridiculous – too dangerous for the acrobat trained from birth who had been Robin for years, but not too dangerous for some punk thief whose only qualification was that he fit the suit.
Dick’s origin has been retold and rejiggered a bunch of times since then, but that original version still stands as the best. As for whether it squares with the show, yes, it does. Dick’s anger toward Bruce had different motivations, but all the moving pieces are the same.
Dick started his life as a performer, happy, open, comfortable in the spotlight. Working without a net meant that he had an unwavering faith in his parents, trusting them implicitly, both to train him and to be there to catch him when he fell.
So his life with Bruce – unhappy, closed off, hidden from the spotlight, no faith or trust in anyone – was antithetical to Dick’s nature. So with the show it’s more about violence and in the comics it was Dick outgrowing Bruce’s restrictive, illogical crusade. But in both cases it’s 100% about identity. “Who am I?”
And the answer in both cases is that he isn’t simply his parents’ son, Bruce’s ward, or Batman’s partner. He’s an amalgamation of all of those things, and he reached a point where it was time to acknowledge that and forge a path of his own. In other words, his parents taught him to live by his heart, Bruce taught him to prioritize his mind, and he needed to find a way forward that would allow him to do both.
He wants to be a crimefighter, which doesn’t allow for the level of openness and trust his parents instilled in him. But he also wants to be Dick Grayson – to embrace some level of hope, faith, and compassion; to allow for love and connection with others – which doesn’t allow for the distrust, deception, solitude, and obsession that Bruce instilled in him.
So I think the show gets it right. They’re just being original with it; showing it to you from a different perspective. He leaves Bruce and Gotham but still wants to fight crime, hence the badge. But it’s not enough. The system doesn’t always work, hence the mask. He left home, but the shadow of the bat still looms over him, for better and worse.
And Dick doesn’t use guns in the show. Batman can be brutal with his fighting too, I think they take a lot of inspirations from BvS fighting wise (Robins fight scenes so far look similar to Batfleck’s).
Tldr; I highly recommend to give the show a chance, every episode is better than the last one so far and it’s actually good. If you think Dick kills you probably only checked the trailer, even then the actor playing Dick said before the start of the show that Dick doesn’t kill.