Re the LO coating, LO (if you see what I mean), the stealth layer is, more of less, an integral part of the skin structure. It's good and it's tough, but it cannot easily be repaired or (as mentioned earlier) be resprayed between sorties. Now, I'm certainly not saying that's a bad thing, it will hugely reduce routine stealth maintenance, but it does make chips a lot more difficult to blend in. As the aircraft design has ad to accept so many compromises to ensure the stealth, it means that the stealth has to be well maintained.