My schnauzer is very nervous, timid, and doesn't like change... what's wrong with him?

I have a 4-yr-old miniature schnauzer. He's been a really great addition to the family since he was a puppy, but he has always had a few problems since we've had him. He has never enjoyed taking a bath. When he hears bath water running, he runs for my dad or brother to protect him. When my mother or I pick him up to take him to the tub, he will either cry or growl... I swear we have done nothing but love him since we've had him, he has never been abused or hurt by any of us, and we have has him since he was about eight weeks old. He also hates change, for instance, just the other day we bought a dog carrier to take to a hotel that we will be staying at this weekend while visiting family, and he absolutely wouldn't go in it. My mother finally pushed him in, and he wouldn't sit or lay down for about 20 minutes. After a half hour later, he began to cry and make "schnauzer noises" (if you have a schnauzer, you'll know they make very unique vocal sounds). He also gets very nervous when someone is carrying objects like belts, yardsticks, and baseball bats. I swear he has never been abused! We have been very good, loving dog owners... Is this just his personality, or can this be fixed?