Life is too short to worry about these things.
Not wearing proper attire to weddings and especially to funerals might also hurt people's feeling who are close to the deceased or the happy couple. I don't mean that you have to wear a suit for these occasions at all but during these events a proper attire is a sign of care and compassion.
It all comes down to knowing yourself, your business, your clients, and your clients' businesses.
If you can't tell when to wear a suit or not, wear a suit. If you can tell, you don't need this advice.