I'm surprised "Bitte" --> "btte" was a hurdle. "Bitte," or "please," is ubiquitous in German. The more common the term, them more likely you'd be to see some contractions. Dropping the "i" is pretty logical- anyone looking at it would see immediately what it meant.
> i would assume yes, to throw off decyphering. even more impressive that they managed to crack it
Were operators of enigma machines aware enough of cryptology or the weaknesses of enigma, for that to have been done intentionally to prevent decryption? I doubt it, otherwise _many_ things should have been done _much_ differently by the operators.