Having acquaintances and knowing the difference between them and friends is an important skill. It's also wise to understand that the term friends isn't all-encompassing and can define various people in our lives, as you say.
I would much rather a few good friends and some acquaintances than many of both, life is simpler that way.
Every day in our lives there are signs and tokens of affection everywhere, maybe we don't always notice it...but I know when a person walks beside me...then he is a good friend.
I agree, and as long as the friend is there for the right reason then all is well.