Dwayne claims that he's using cube steak for the kebab. Cube steak is a cut of sirloin that has been severely tenderized and is usually both thin and broken up. The meat used is clearly not cube steak, and cube steak would be completely unsuitable for kebabs as it would likely break apart and fall off the skewer.
When Rock is demonstrating how he makes grilled cheese sandwiches on the job site, he begins by spreading a "generous dollop of oleo" (margarine) on the bread, then placing the cheese between the slices of bread. However, he places the cheese on the side with the oleo, thus placing it on the inside of the sandwich. The whole point of buttering the bread of a grilled cheese sandwich is that it be on the outside, thus causing it to grill. Otherwise, it's just dry toast on the outside and wouldn't be very appetizing.
Jill says that "Evil Woman" was released in 1976. She's only a couple months off, but was released in October/November 1975.