Sympathy:)
You and your husband each have a good point.
He wants to discipline the poor behavior. People have posted good ideas about this, e.g. resources and discipline. Throwing apples and drawing on the walls and shades sound like things she should know she shouldn't do! Like syoblrig, I am a big fan of a kid cleaning up their own messes...
Your point is also important. You said that you want to find out if something is causing her behavior. While this may be a passing phase that can be solved through discipline alone, there may be other reasons for the poor behavior.
From what you wrote, it sounds like she would repeat behaviors before preschool (e.g. driving the car around the living room) but that the behavior has worsened since starting preschool, and that you had considered SPD.
Other posters have recommended various things that have helped them, but I would look for a diagnosis/cause before knowing the best way to handle the situation. A PG kid in a preschool can feel totally lonely and overwhelmed. A kid with a vision problem, a hearing problem or a sensory processing problem can find preschool overwhelming. Sometimes, the preschool experience can push a child who is coping with something over the edge and it's an opportunity for the parent to learn more about why some things are so hard for the kid.
Feedback is: you're so smart to ask about this, so smart to think about how to work with your spouse, and right that this sounds like something you want to figure out.
While you are exploring what's going on and selecting ways to discipline, may I also encourage some fun:) When my child was this age, a trip to get a snack or dig in the sand or visit a favorite place always brought out the best of both of us! No mess to clean up, someone feeds you a snack, you are giving you kid attention for GOOD behavior, and you both feel wonder and interest in your activity. Just a thought that focusing on some good moments together might be a relief and a pleasure.
