I Want to Flatten my Top Sharp 'Canine' Teeth. How Much Should Should This Cost Per Tooth?

Correcting the midline is a definitely correctable condition with several possible treatments including bonding, veneers, and orthodontics.  The key is to visit a good cosmetic dentist that can see your particular situation and advise you of your unique choices.  Good luck!

You stated that they are replacing ill fitting crowns.  As long as the temp crowns are well fitting and cemented properly there should be no problems with getting decay or with them popping off.  If one does pop off you can always recement it.

Esthetic crown lengthening can make your canines larger if you have altered passive eruption.  Meaning your teeth have not completely grown through the bone.  If your teeth have grown completely through the bone then a simple gingivectomy can be done to make the teeth longer.  

If you are looking at long term solutions, either option will work.  If you are looking for long term aesthetic solutions, I would go with the implants.  This will give your son 1.) more teeth to function with, 2.) a more natural smile, and 3.) more confidence in that his teeth and...

Once you remove the loose 2nd molar, it'll take years and years for your 1st molars to drift back.  I wouldn't even worry about your front bottom teeth spread apart because they won't.  If you lost all of your molars on one side, then yes, your premolars and front bottom teeth may...

I have never heard of a dentist filing down or reducing enamel on a tooth without consulting the patient. When your teeth are filed down, he is reucing the enamel.  If the front teeth were too long, it would have made more sense if he added and contoured the side teeth to match. I am so so...