No, it's not too much.  It would be a great way to help maintain the benefits you got.  Just be sure you are really sun protecting.  I often advise stopping it a week or two before a sunny vacation because we all tend to be less careful then.

On your second question, that's hard to say without seeing your skin.  But in general, you don't need to go up to the CO2 lasers unless you still have a lot of sun damage or wrinkles.    Dr. I