LeviM,
Your are correct when you say that the stiffness values are for each bellows in a universal expansion joint. As a result, the values will be very high. The effective universal, overall, stiffness will be substantially lower for lateral and ½ for torsional. I see where you’re using the minimum number of cons, ie 4, you can reduce the values somewhat by increasing the number of cons in the input sheet.
In regard to how to specify an expansion joint, I’ve attached a sample specification which you can use. There is a sample datasheet at the end where all you have to do is fill in the blanks.
I hope the above helps,