Am I good enough even to worry about the fin setup?
It is true that small fin adjustments are more noticeable to higher-end skiers, but all skis need to be set up properly to perform well for any level of skier. A poorly set up ski can definitely hinder the progress of a skier at any level.
Why should I only make one fin adjustment at a time?
If you make more than one fin adjustment at a time, you may never gain a full understanding of what each movement does to your ski. Just as in a science experiment, there is a control and a variable -- but more than one variable can create worthless data.
Do I really need a wing?
On most skis designed after 2002, a wing is commonplace. True, the wing does create a little drag on the ski, but it is more obviously associated with the stability of the ride: It allows the ski to track much more predictably and finish the turn with a greater amount of control.