The only buildings that do not have any king rooms are in Trinidad. You can be put in any other building other than in Trinidad. So if they are able to honor your request, you could be close to either station.
No, WDW resorts no longer have fax machines. Your best bet is to call the main reservation line and add your request to your reservation.
There's no negatives to doing online check in now. Just do not make any requests in the online check in process.
Your best option would be to word your request as quiet location near the bar or skyliner. That gives the room assignor lots of options instead of requesting a specific room or two. If those rooms are occupied they won't know why you wanted them.
Disney resorts have a couple different models/types of thermostats. Which one you have will determine the button push combo you'll need to use to override the 68 setting.
You will definitely get more replies if you post your questions in the links below
The Grand
https://www.disboards.com/threads/disneys-grand-floridian-resort-spa-information-questions-construction-updates.3814628/
Poly...