Medium!
I dont have an answer to your questions, but
I have pretty much the same symptoms as you do! Except my tounge isnt white (yet?) and havent noticed any difference in my gums.
What toothpaste do you use? It started happening to me right when I started a new toothpaste and havent changed toothpastes again yet so Im still with the same one. Thats what I thought was causing these wierd symptoms but maybe I was wrong.
I also have the strange white lines on my cheeks and experiance a very very annyoing and unusual "goo" in my mouth shortly after I brush and in the morning, it only happens after I brush-like yourself.
I go for my usual 6th month dental check up next week and was going to wait till then to ask my dentist, maybe I should go to a doctor earlier..?
I will let you know what I find out, would you please do the same?
Thanks!
Take care