I was circumcised at birth and I masturbate without lube the vast majority of the time too. I have enough skin that I can roll it over the base of the glans, or crown, even when erect.
There are varying degrees of tightness as the result of circumcision. Some men may grow to have extremely tight foreskin when they have erections. However, I'm not sure if it's a problem with adult circumcision (but you should ask and mention it anyway), because as an adult the size of your penis is already known and therefore I'd think the correct amount of skin to be removed could be properly determined.
As for your other questions, just ask when you go in for the check up. Write down all of your questions and concerns as they pop in your head, and bring it with you.