I am from Branson. Take it from a person who used to work in Branson at a tourist attraction.... don't do it! SDC DOES check ID's. Even if it's at random. Every time I've gone they've asked everyone before me in line for ID's (they even checked mine - and I got in free for working in Branson so I'd have to show my ID and work pay stub at a different place before even going through the gates). It would be too risky to try. If they did ask for your ID and it didn't match with the pass, your friend would risk losing her Season Pass (and I know how expensive those things are) and it would be embarassing to you, I'm sure.
And, you DO have to have your pass to get in the gate (you put it in a machine or they swipe it through a machine), so it's not like Costco as a PP said. I lived there for 14 years before moving to Oklahoma last year, my parents still live there. I worked there for 9 years.
They used to mail out friend passes to SDC Season Pass Holders every year where one of their friends could get in for free for one day. I guess they've stopped doing that? I do agree that these places are PRICEY!!! I won't go there with my family unless we get in free (my dad sings in a show there, so we are still able to get at least one of us in free when we go because he can get himself and a guest in). I can't imagine the cost involved in that kind of a vacation.