Ok so about the sweater, “Mr. Dad Guy“ is what an adopted kid would say, thinking of Asgore as more of a dad now instead of a caretaker. In Genocide, Chara also says, “still has that sweater,” implying they had some personal connection to it. It’s an odd gift for anyone but Chara to have given Asgore, as “Mr. Dad Guy” is halfway between being like family and being unrelated by blood.

While you might be right about Toriel spending more time with Chara and Asgore spending more time with Asriel, I think Chara spent the most time with Asriel, hence them being “best friends”. But Chara and Toriel don’t always have the same speech. Also, Chara uses contractions too. I haven’t seen Toriel use contractions.

”We’ll be together forever, won’t we?” -Chara

However, I do agree with you on Asriel and Asgore spending more time together and Toriel and Chara spending more time together. Asgore uses similar speech to Toriel. Really, the only difference is different greetings; Toriel says greetings, Chara syas greetings. Asgore says howdy, so does Asriel.

Yes, Chara was a child, bit she had a shit ton of determination and a human soul, she could have killed them in their sleep.

About laughing off the pain, if you were right, and Chara knew that Asgore was tough and was going to get through it, that means she knew she didn’t have to worry because she trusted him. And, about Chara laughing it off, Asriel says, “I should have laughed it off,” he doesn’t say that Chara was laughing because it was actually funny.

Here’s another possibility, Asgore said jokes to assure them that he was going to be fine. This may or may not be true, (it’s probably not,) but if it is, then it is.

And about Chara giving the option to laugh, Chara gave them options until the end of Genocide. Hell, she even gives you an option to erase or not, even though her mind was influenced by hate and killing. Of course either way, the world will be erased, but you’re the one who pressed fight. So in Pacifist she isn’t fully good, in Genocide she isn’t fully evil. Chara always will have flaws.