Whatever you like or feel comfortable. I remove,because I don't like it,and it bothers me,and I would be like a werewolf. :D

That depends if you are a hairy woman or that your hairs are dark that they make you look hairy (theres a difference).
I realised that my hairs look natural and less noticeable in the sun but during winter there very noticeable. I wouldn't recommend it because you just have to do more work to your body. You can always sunbathe or spray tan if you feel that self conscious about your hairs. Also if you tryed shaving your arms will obviously feel prickly. I have never tried removing my arm hair and I never will, but this is just me.
I hope this gave you any ideas on what you are deciding, you can even try writing down all the positive and negative effects if you remove your arm hair or not, so you have your thoughts on paper :)