I like some graphical yummyness. Therefore I like these ideas. I personally would like the shield flag to give a goldenlike glow. But there should always be a server option to shut it off.
The way it is currently implemented is a bit unsystematic.
For instance, Why does Tiny look different, but high speed doesn't (both can make you dodge bullits better). Or, why does "Obesity" make the tank look different, but "Left only" doesn't (both make you sitting ducks)?
For the "experenced users might get an advantage"-argument: Experienced users, already have an advantage, because they use the identify button. The rookies don't know howto or cannot use it fast enough. I don't want to win a dogfight because I know how to use a button.
B.T.W. Experienced users use the radar most of the time anyway. This might actually make them look out the window.