A:AnswerI wash my hands very frequently as I work in a Spa, I have not had any issues with getting my Apple Watch wet with the clear shield on it whatsoever. The clear shield actually applies so seamlessly that you can barely even tell its there, I would not see you having an issue!
A:Answeryes it would work with or without bumper but in my opinion its safer with the bumper though it has to be a bumper that has a good grip cheap ones will peel of the corners
A:AnswerYes, get the Belkin screen protector and a slim case for your watch. The Belkin unit doesn't go around the curved edges making it easier to put on. The case will protect the edges. I would pay the $7 more to have geek squad put the protector on. I'm confident I could've done it myself, but it adds a little piece of mind that if it goes wrong it's on them and I believe they will get another one off the shelf to do it again.