Congratulations. How exciting and nerve-racking, too--only a week to get ready!
I agree that you should rent chairs if possible. You know your guests and I don't, but I think many would be grateful for somewhere to sit after a walk on the beach. Age, health and heat would be factors as to needing a rest and being able to really enjoy your ceremony. I don't think you need music, either, but maybe a guitar or something simple like that might be nice.
The tins are cute and the corsage is adorable. I'm looking forward to seeing the pictures of your wedding. Best wishes and good luck