Holy you are still a teenager and your already know what sup!!!
I concour on alot of those things, but I think the pros out weigh the cons in my opinion. Responsibility is like you said part of "adulting" and as much as I hate doing that, its still a part of me, seeing as Im in my 30's now I still feel 22 thou and look it.
but no fotografer??? u kids and your selfies, you dont gotta be in every single foto. use your memory, take a picture with your eyes and remember it forever, that way it'll never get deleted.
and like you said fun with friends is great but make new ones!

good post thou, get out there and keeping making friends. i still do to this day!