TevaMen's M Langdon Sandal

can you wear these as water shoes?

My top straps are almost too short & the heel strap doesn't make it. Is it a good idea to move the hook strips closer to the loops strips by sewing?

I have latex allergy, what are foot beds made off?

In size 9 mens, what is the measurement of the footbed from side to side of inside strap area?