[Adam the Fish]

Hey,

Not being a scientist is any of those specific areas, I'm afraid I can't necessarily tell you, however:
Accent is more picked up where you learn the language, although it can change after prolonges communication with those with a different accent.
Other things you mentioned are not entirely controlled by genetics, etc (many hypothesise do exist).
I think that it would probably be helpful for you if you accepted yourself more, though; all the things you mention are part of you, and everyone has different strengths and weaknesses. Love yourself for who you are, clichéd as it might sound.