I agree with you for the most part, but think there's still time to rebound. Just a couple of thoughts.
1. Yep. Me want guns NOW. Show him up up up. Dumb Dumb Dumb.
2. Yep. Although, he was just tossed down into a pit. I thought it would have been better if he'd hurt his leg on the fall, or something to hamper his ability to fight. Then he did impale his hand on one of the spikes. That's gotta hurt. But the keyboard to the helmet was really dumb.
3. Daryl was traumatized at the Savior's compound. The way he killed Fat Joey showed he was under a little stress and hadn't been having a good week. He seemed fine to me until he heard the name Carol from Richard. Then when he was with Carol he seemed fine. I'd like to give him a pass. He is the show's most beloved character, I'd wager. And he'll be fun to watch during the war with Negan.
4. Meh.. Carol's journey has been a major story line in the show. Carol was in full-on survival mode, at any cost... until Alexandria. Because prior to Alexandria, her group was in constant danger. Then the group began to settle into some normalcy, at least for a zombie apocalypse. It was a shock to Carol's system (and to Sasha's as well) and she still didn't trust anyone until some time passed. But she softened. She even began to open up to Tobin, who was sweet on her. She talked with Morgan and had time to process the point he was trying to make about killing humans. She wrote down a list of living people that she had killed since the prison and it began to get to her. She didn't like the person she saw and decided she didn't want to kill again. But, after the Wolves and all, she realized if she stayed there she may eventually have to kill again, to protect people like Tobin. She didn't want him or anyone else to get close to her and she went into a shell. She eventually thought it best to leave. She didn't know how she'd react if anyone threatened her but she was prepared with the gun up her sleeve. She got her answer when the Saviors stopped her. She killed and then had a break down. Morgan finds her and brings her into the kingdom, another peaceful place. Like in Alexandria, she doesn't want to get close to anyone or have anyone get close to her. So she leaves the kingdom and chooses to live alone in the house.
She was meek at first, then became tough when she realized it was necessary to survive and to help her group survive. But when things calmed down a little she got to reflect on what she'd become and didn't like it anymore. I think we can all agree that we like her in survival mode and want her to want vengeance on the goobers that killed Glenn and Abe. And time will probably accommodate that.
But she is not a "delicate flower who can't be given bad news or it'll upset her." She's already upset. She's a damaged and confused killer. She was coping well, then she sees Daryl and those feelings came back. She thought about the group she loved and didn't want to see or think about them being harmed. Daryl recognizes that it wasn't the time to tell Carol because the only news that would give her happiness was the news that everyone is okay. IIRC, when Daryl leaves her house, he is leaving the kingdom and going back to the hilltop. He's giving up on Richard and Ezekiel and seeking help elsewhere. He'll try to destroy the Saviors himself if he has to. But he doesn't want to put Carol in danger by dragging her with him on what he might consider a suicide mission (if it comes to that). I don't have a problem with him not telling her about the deaths and what he went through. She'll get caught up on what happened from someone else.
5. Agreed on Tara keeping silent. That was annoying. But, it was at the end of the episode. I'm guessing she either tells Rick about Oceanside, or she goes back to Oceanside and tries to talk to the daughter that she befriended and ask for their help. If she doesn't get it, maybe she'll disclose everything to Rick and Michonne and they end up taking Oceanside or something. I'll give her a chance to speak up before concluding that she is a moron for keeping a secret promise at the expense of her whole group's survival.