I have been composing custom wedding songs and singing in wedding over 25 years. I will offer my advie on wedding music and how much is appropriate.
Once the wedding ceremony begins, the couple will want it to move quickly. I suggest a song right before the ceremony, music during processional and song during candle lighting (a short one).
Couples really get uncomfortable when songs drag on. so does the audience.
Thanks!! Your advice actually helps a lot!! I'm not sure if you read my post, but my fiance and I were trying to figure out how much was too much! I guess now we know!!