No, the supply voltage is 12V!! take away the forward voltage of the LED and you have the voltage you need to kill off with a resistor 
You sure?? I'll trust you, as this is ne of those electronics things i often had trouble with!!

I suppose if its tested before its put in, it wont be a problem.
i like the idea of having them in bith tho 

At least someone likes my ideas, don't happen often!! :'(
If your going to get the diodes cheap from somwhere, i'd grab a load, test a few different circuits (keeping them, so you can compare) and then with the final circuit happy, get some high intensity ones, just to make sure! The forward voltage shouldn't be much different, but will obviously need to be considered. Glad to help!
(if its helped!)