Aarti Lala, DDS

I would suggest get in-office ZOOM WHITENING first so your teeth can get 2-3 shades whiter in just an hour, then have a crown done on that tooth. Maintain the white shade by using take home ZOOM whitening gel.

Zoom in office 500-600

Crown 1200-1400

It is definitely in your budget to get a sparkling smile :)

It is a very small chip. Ignore it if you can, or the most permanent thing would be get veneer. You can get composite bonding on the edge of that tooth but it might come out due to the location. 

Looking at the crowding of your lower teeth, I would recommend orthodontics-Invisalign or braces. Veneers or crowns are not a good option for you to align those teeth.

Hope it helps.

You can either get new crowns or removable orthodontics to close the gap. If you are missing any of your back teeth, your teeth are constantly shifting and I would suggest orthodontics with retainers. The treatment in this case is based on the cause of the gap. 

Hope that helps.

If it hurts only on biting or chewing, you might have to go your dentist again to have it filed down. He can numb that tooth and adjust the crown. Make sure he takes that tooth completely out of bite. But if it is a constant pain, you might need a Root canal then.