Yes, and I apologize for advising you to return your tree, Max. I had assumed wrongly that you were in Florida. As far as I know Citrus Greening has not spread to any great degree in California.
Leaf miners don't do anything but cosmetic damage, and by the time you see it the bugs are already gone so there's no need to worry about that. But the leaf curling you're seeing could have been caused by aphid or scale damage early in the life of the leaves, as well as the things Daniel talks about above.
Keep an eye out on the new growth for both aphids on leaves even before they open, and scale on the stems. The green stems will appear bumpy instead of smooth if there are green scales attacking them. A horticultural oil spray will kill them but on a tree as small as yours, you can probably just strip them off with your fingers. As for aphids, an occasional spray with the hose usually keeps them at bay.
