Oh, and is it okay to put water and fresh flowers into a vase, or will it
leak/ruin it eventually?
Another suggestion for your vase is to include a glass jar in it -- the clay
shape on the outside doesn't have to rely on the jar shape for it's external
appearance, but the jar would assure that no accidental air holes exist, it
would give some structural support, and add some weight so the flowers don't
tip the light-weight polymer over. It's not essential, but it might be
helpful (Think of the jar as a liner.)