I had/have all those symptoms. Sometimes I can eat whatever and other times I am so tight I can't even eat yogurt w/o PBing. It's a tempermental little thing. I have found some things that help when it is too tight.
I have to drink Water before eating so that I do not have spasms which make it so I PB. I have to start with something very soft and eat it very slow. Then my esoph. starts working right and then I can eat regular food as long as I chew well and I can eat about a cup of food.
When it's been wide open and I am able to eat even bread, I have found the secret to make it tighten up w/o a fill.
I go on liquids only for 1 to 2 days and keep it at about 700 calories. It works and I am tight when I go back to regular food. It totally gives my band a jump start.
A few days ago I think something bad happened and I am going to go start a post and ask some questions about that.