There is no limit to the angel perk: the more you collect, the higher the chance of ammo drops. It does carry over between levels, but if you die/quit it IS lost.
Oh, I think there may be a bug with the labyrinth secret. I submit them in what I believe to be the right order, based on the top left structure in forever alone - next to the run down house, but it doesn't unlock or play the jingle
While we are on the topic, some of the cutscenes have an issue where the first word in a sentence is lowercase. I am guessing this comes from you using capslock for the majority and then trying to capitalize out of habit.