Judging by the LB, you have a submersible and the purpose of the well seal is to keep surface water from contaminating the well. The fact that it appears to be flowing out of the well means your well is either artesian or you have a leak in the pipe right at the seal. If you turn off the pump, does water stop coming out the well cap?
My guess is that the system either has a bleeder/snifter/checkvalve to air charge the tank or a micronizer and that the air volume control on the tank doesn't work.
I think you first problem is that you are calling in plumbers. What you need is a pump man, not a plumber.