Can my baby's name influence his personality? Our astrologer seems to think so. Is it true?

I would say - NO. A baby's name has nothing to do with a baby's personality. As long as the name is pleasing enough, a name is a name. Your baby's personality will be influenced by a host of other very important and realistic things, such as what values you teach, how you do things at home, the way you respect others and how you behave with your baby as well as others. All these are strong and very influencing factors.