I feel confident of my ability to play an insidiously intelligent character, but I know what you mean... when my character slips verbally or otherwise, it's embarrassing and awkward, especially if it's unanimously OOC. There should be medals for portraying characters excellently, since in the end the portrayal is only as good as the player.
You're doing fine. Please try not to take things personally... Light's player and I are practically in hysterics (laughter), since we seem to have caused a fair amount of unrest. He and L are so darned rambunctious... The little FUBAR scamps, frolicking all over this RP. XD Burning people's eyes out and the like... really. They prove that there are worse things to feel guilty or responsible for.