Make "backspace" behave like in an ordinary editor (e.g. delete empty lines):

set backspace=indent,eol,start

Comments lines with ", + comment_sign"

map ,# :s/^/#/
map ,/ :s/^////
map ,> :s/^/> /
map ," :s/^/"/
map ,% :s/^/%/
map ,! :s/^/!/
map ,; :s/^/;/
map ,- :s/^/--/

Delete comment control sequences from lines:

map ,c :s/^//\|^--\|^> \|^[1]//