Not a lot of questions. Totally a normal amount of curiosity!
I wouldn’t say it’s quite the same as Astrid’s relationships in WH. Not as close/personal, because she doesn’t have that initial bonding experience with Stormfly. She’s really closest to Toothless, because Toothless is kind of like the fed-up roommate of the drunk asshole who apologizes when said asshole throws up on the carpet, eats your food, kidnaps you from your friends and family and treats you like a dicksicle… Toothless has kind of seen his rider harden over the years, and while he totally isn’t a fan of having Astrid in the cave initially, he also feels like, “Hey. Dude. You don’t have to be that rude.” He keeps an eye out for her– steals that fur for her the first night, makes sure Hiccup saves food for her in those first couple of weeks when he’s still learning to remember there’s another human to worry about. If he had hands, he’d be smacking Hiccup upside the head every time he says something ass-ish. Sometimes he still does with his tail. But over all, yeah, she warms up to the dragons and begins to see them the way Hiccup does. Once they actually start being civil (sex mellows you out, dude) and having conversations, she can begin to see that the dragons are compelled to serve the queen.
Hiccup doesn’t necessarily plan on teaching Astrid how to ride, he just kind of figures might as well. He wants her to be able to get off the island if there’s an emergency, and she starts accompanying him to work some nights. (I really need to explain this. He has a system of about six islands that he shuffles/shoos the dragons to every few days. That way when they attack, they hit one place at a time, and that island has time to recover before their next turn in the rotation. I keep saying I’ll get into it and never do.) Though he won’t say it to her, he knows that teaching her to fly means accepting that she’s going to find her way back to Berk– and she does. But he teaches her anyways, because he’s falling for her, and she comes back before she even touches down on Berk’s shores. They don’t tell each other how much they don’t want to separate until Hiccup takes her to Valka.
As for Oopsie, I haven’t fully decided yet. I was actually thinking on it last night. I probably won’t take this all the way to Oopsie’s birth, but I’m leaning towards a boy right now. Might still go girl, though, no definites yet. Generally, I think the darker I write Hiccup, the more likely I am to give him a boy firstborn. Idk wai. Hashtag writer issues.