(English is not my native language, please bear with me and my possible mistakes)
I’m not sure Steel bombed the place himself ? I always assumed he called bombers or something. It would be very concerning for the MC if he truly had the power to make an entire building explode.
We never spoke about injuries with them, so we have no proof they were harmed. But in seven years, they apparently had time to accumulate new scars. I don’t think the MC would be able to differenciate a scar dating back to HB from another.
I honestly don’t think Ortega is aware that MC is a Re-Gene. They looked genuinely confused after we froze during the make-out session. And yes, they changed a lot after seven years, but I’m pretty sure we still know them enough that they cannot flat-out lie in our face. (They already looked so akward when they were talking about their ‘friend’ in the suspicious path, even if the MC didn’t pick up anything). Plus that and their insistence to understand why we are so messed up and how to fix us. They might know we are a villain in some paths, but as for our tattoos, they seem to have no clue.
Same for Steel, we didn’t interact a lot with him, but there are enough clues to point out he was also affected by Heartbreak. Ortega said in book one they had to channel their father to stop him from doing something drastic, and they both said the dampeners have been overheating. So far, they are telling the same story. No reasons to doubt them.
The reason why Ortega didn’t participate in Steel’s investigation is, I assume, because they had no idea there was an investigation going. Put it in Steel’s perspective: his friend saw their partner go through a window, and was told they died shortly afterward. They were so traumatized by this event they dropped their position as a Marshal, became a drunkard, and needed severe therapy. Now, there might be a chance that something fishy is going on, maybe even their partner might be alive. But what if he were wrong ? What if Sidestep was really dead after all, and it was just his paranoia talking ? I don’t think Steel had it in him to give hope to Ortega, just to watch them get crushed again. Ortega was probably a huge mess at that time, they couldn’t have taken another emotional hit lightly. And in the end, Steel didn’t find us after all.
Also take in account that when Ortega left and put Steel as the Marshal, they left him with a huge mess to deal with. There were four known Rangers before HB, unofficialy five: Anathema, Sentinel, Steel, Ortega and unofficially Sidestep. After HB, only Sentinel and Steel were left, and it looks like Sentinel retired not long after. So there was a time when there was only two Rangers to protect the city, maybe even a time when Steel was all alone to bear that burden before Ortega came back from retirement. He is still hiding something from us, but it is also true he was too busy trying to keep the Rangers from falling apart to properly investigate our case.
Mostly, I think the MC is mad at Ortega for not questionning further their role as hero in this society, which could have maybe saved us back then, or at least gave Ortega a clue as on to what was going on. When we speak from the heart during the showdown at the museum with our motivation being ‘I want to show the world the truth’, we say something in the line of “You were given the power to fight for what is right, and what do you use it for ? Doing exactly what they want. Like their loyal dogs.”. So basically, we might want to kill Ortega because they’re a moron, and because they let us down one too many time.