Completely, the mateial used in Evolution bleaching have been used in dentistry for over 100 years.
You may get some tranient sensitivity, however your dentist will give you easy to use desensitising swabs to take home, which work immediately.
No, natural teeth rarely look too whte. Sometimes very white crowns can look wrong because they are made of porcelain.
Enlighten Evolution bleaching can whiten teeth up to 16 shades, results vary but if used correctly all teeth will whiten dra,atically.