Why are my parents so strict and overprotective?

I'm 15 years old and I'm half white half Hispanic. I'm adopted by Indian parents and they are very mean, strict, and overprotective. My mom has a horrible personality and she always yells. Like when I would ask her "did you finish all the food, or is there still some left" she'd kind of yell instead of responding calmly like "NO! I Didn't finish it! Unless YOU ate it!" So that makes me mad and I always have to be like "ok, ok I'm just asking". Both my parents won't get me a phone till I'm 18 and they won't let me have any social media. I joke by saying "I'm going to save my money up for an iPhone" because I know they get annoyed by it and they'd be like "no iPhone, you're not getting that. Think of something else." and even if I do get a phone, they'll put all kinds of family monitoring apps and make sure I can't use it pass 10. I'm more mature than they think, but I don't know how to prove it to them. I'm home-schooled and I have been fore the past 3 years because I got bad grades in middle school. They won't put me back in school because they still think I'm immature and I won't do my work. I try talking to my mom about it, but she won't listen. I have a laptop, but it's only for work and they put Qustodio (family monitor to see what your child is doing) on it and even with that on, every time I have to do work on it, I have to do it in front of her with the screen facing her because she still doesn't trust me. There's much more to say, but I can't. I don't know what to do.

Why do you have to install messenger on iPhone to view messages?

It won't let me simply check Facebook messages on the internet. I do not want to install Facebook app or the messenger app because i Rarely use Facebook and rarely do I get messages so it's stupid to install something I don't use. Do they gain something from me downloading the free app? I have to use my laptop to view messages or never read them.

IPhone Screen Replacement and AT&T Next?

I have an iPhone 6s, and I cracked my screen. It is under AT&T and AT&T Next. I'm not planning on upgrading any time soon, but I want to replace the screen and would rather replace it myself with an OEM part than pay $120 for the same thing. I have 2 questions: 1.) I've been told that OEM parts are the exact same thing as the original parts, so does it have all of the markings and stuff? And 2.) Would AT&T check or even care? I know that there are serial numbers on most parts in the iPhone and I assume it's matching for every part, so I was wondering if they check that and if they would care if they found out that I opened it and replaced it.

IPhone 7 or IPhone 7 plus?

I'm deciding on which one to get. I don't really mind the size but I'm just curious which phone has the better camera. Do both phones have that blurry background photo effect?

Would 2GB of Data per month work for someone that doesn't use their iPhone much?

I'm asking this question again in hopes that it makes more sense than my first question.

I just got a new-used iPhone and I don't use it that much. A plan hasn't been started yet and this is my first smartphone, so I was wondering if 2GB data a month would work for me once I get a plan? I know this question sounds silly for most people but like I said, I don't CONSTANTLY use my phone! I'm always doing stuff online but I do that through my laptop instead of my phone because it's easier to use the websites on a computer than a mobile device. I'm also not someone that uses Twitter or Instagram or other social media sites except for Facebook every now and then. I also don't stream stuff like music, the radio or whatever. It's just not my thing.

I mostly want the data just for something to do during my lunch break at work. Most things I already do is what I plan to use only for Wi-Fi. I will most likely play some games, watch a couple YouTube videos, and surf the web a little during my lunch. I know streaming videos can take up data quickly (if you constantly do that) which is why I wasn't sure how well this plan would work for me.

Anyone have any advise for me? If you think 2GB isn't enough, then what should I use for data that's not connected to Wi-Fi? I will get more GBs of data if needed but I just don't want unlimited data. Please be nice otherwise your going to be wasting your time. Believe me, I know better.