Carolyn, welcome to the boards! I am just home from nightshift at the hospital, so forgive me if my phrasing or typing is a little off!
I didn't actually read all the posts until now, just the first page and a half approx., so I may have missed some new important details.
From my perspective, there are several comments I'd like to share because you've obviously received a number of varying viewpoints!! LOL
Regarding the cookie crumbs, which may or may not have contained peanut: (Aren't most bakery items now listed as potentially containing traces of nuts just due to the preparation being done with other foods that do contain nuts? - in which case it might not matter whether they were specifically peanut, but that's getting silly!)
Absolutely right to notify the staff about the unclean room with cookie crumbs. I agree that you pay through the nose for a deluxe hotel (or any disney hotel for that matter) so you shouldn't feel you have to accept an unclean room. Heck, when you first enter the room is when it should be at its cleanest, and crumbs on the floor, regardless of any potential allergies, is unacceptable. Of course I say this, and then would have difficulty finding the right words to use when speaking to staff about it! Probably would have found myself tactfully asking them to clean it (then been annoyed at myself later on for being like a doormat!)
The flip side of the coin is in relation to the allergy. True, peanut allergies certainly can bring about anaphylaxis. Haven't fortunately seen it myself although probably will when I work in emergency medicine in my next six month job! By the way, do you carry an epipen? Probably should. You could realistically ask for a fridge to store epipens in while at the hotel. Unfortunately the difficulty with this type of argument about this allergy is that it could occur with non-deliberate contact with anything peanut-related. So as everyone knows, this could theoretically occur anywhere at anytime - despite your being a good parent, you can't possibly be aware of every little thing at every little moment!! You'd have to be a stepford parent for that!
So, my point on this is that the allergy could be triggered at anytime, and it can't be WDW's responsibility to prevent it, except for the usual measures which include well posted food ingredients and hygiene. In theory and hindsight it would probably be best to notify the hotel in advance of this allergy to give them the opportunity to pay extra special attention to the room etc, and organise a fridge for your epipen storage.
About the sliding doors... gosh, I was shocked that your daughter managed to open them (but not disbelieving) as they are heavy and the handles are usually about half-way up them. But, I am aware that they do tend to leave them unlocked. Being three adults we don't normally need to check them, save to make sure that our valuables are safe in the room when we go out. Obviously that is a concern for you and you were right to mention it to the manager in a friendly and concerned way, just as an observation.
I agree that WDW probably doesn't think it owes you anything, but they usually try to be accommodating and I agree they will be concerned that they'll lose you as a guest. So, if the lady gave you a special number to phone, then I'd hang on to it... but I'd probably not go for anything too extravagant myself when phoning it. And also, I'd probably not ask outright, but phrase it round the subject so you steer the conversation in the direction you want it to go in, without being blatently obvious. I think that usually wins people over more than someone who appears pushy. You might like to say that you'd have a few problems on your last vacation and the lady you'd spoken to had suggested calling this number if there was anything you needed help with in your next vacation (i.e. this one). Did you get the lady's name because that would definitely be helpful to mention? You might even ask the upgrade price to a better view etc (but without obliging yourself to take it) and see what they say, or if they offer it free.
I love WL and have stayed there twice. We would definitely like to stay there again on further trips. All this is JMHO! I hope I've partly answered what your original post was about, and gathered a few of my own thoughts on what the question seemed to have become.
Have a great time when you next go to WDW, Carolyn!
John