Shift and + takes me to first non whitespace character of the next line. I expected that
Shift and - would similarly take me to first non-whitespace character of the previous line. But, it does not. Could you please tell me why?
To get to the first non whitespace character in the previous line you send the minus sign to VIM, you do that just by pressing the button next to the equal sign and plus, you don't press shift to send the minus sign. If you press shift and then the button containing minus then you are sending VIM the underscore signal which is not what you want.