The first Program to have a Death Opportunity is Proxy, your local petty criminal. When she appears at the Landing Platform, you must let her pass. If you do not, you will be forced into a situation where you will have to defend yourself against her - and she will die.

So let her in. What harm could it do, right?

A lot of harm, actually.

Once you let Proxy in, she will inevitably attempt to kidnap Prinz for his knowledge on the Key. Once you are up on the landing platform with Proxy holding Prinz hostage, let her escape off the roof with him. If you try to stop her, you will throw your disc, and derez Prinz instead.

I maintained a high trust with Prinz prior to this scene. So far unsure if it affected the outcome. To gain his trust, note that he finds reputation extremely important, and always side with Users when asked.

This will be the last time you see Prinz and Proxy. It's fine. They're alive.

Now, with Ada your mileage may vary.

In my playthrough, gaining her trust lead to her invariably dying to Cass' explosion, and no amount of persuading-seeming dialogue options would stop her from running toward Cass. In order to not gain her trust, I opted to keep Sierra imprisoned. As such, Sierra and Ada will be rather cross with you, but they will both remain safe and sound in the library. Another win in the "everyone lives" department!

Even if they both hate you for it.

For this run, we've basically pissed off Grish in every way possible except letting Sierra go. As such, he's not very pleased. He will confront you in the Lobby, and again on the Landing Pad once you've made a quick escape up the elevator (unsure if not dodging the motorcycle was a requirement, but in case it was, I didn't dodge the motorcycle in the beginning).

Let him take Cass back to the Vault - this will unlock "Safety Measures", anyway. It will also allow him to survive this encounter - if you don't let him take Cass, Cass will step in and kill Grish. So lets... not. Do that.

So far, I have not managed to get Cass killed myself, I must admit. It seems, however, that a death opportunity can present itself in the confrontation scene on the landing pad with Grish. It is absolutely paramount for the deathless run to let him escort Cass back to the Vault, as either Cass or Grish will die as a result of the confrontation if you don't.

Because we let Proxy take Prinz, the Grish "chase" will always trigger. If you choose to protect Cass, Grish dies. If you do nothing, Cass dies. So your only remaining option is, as mentioned before with Grish, to let him take Cass back to the vault.

All in all, the deathless run will probably be one of the most unsatisfying runs to make in this game. You will end up alone. Everyone will be alive, but pissed at you. But alive! So I'm not sure anyone's in a place to level complaints at you in the first place, ungrateful bastards that they are.

I'd be super grateful for any pointers in the comments, so I can extend this guide. I am also not sure if Sierra can die, I've not encountered any endings where he has yet.

Remember kiddos, Tron lives (and now, all these idiots live too!)