Well I'm glad I do! Anyway, I did read the entire thing, several times because it didn't make sense.
If you use clear PVC, what would the point be if it was under gravel anyway, you wouldn't be able to see it because it would be covered. If it was clear, and not hidden by substrate, congratulations, you just pissed the fish off because they can't swim where they want, but where YOU want.
A lot of the people on here will say positive things because they are awesome and don't want to say anything to hurt someone else. Me, I'm more of a realist, and I would like to make sure people see all sides before delving into anything 100%. I love when someone points out obvious things I don't see, it helps me, which is why I was trying to help you.
I'm glad you spent only $10. I get the shop-vac will suck out the dead fish, old food, and other random stuff, but the fact that you're thinking of failure shows that even YOU don't see this working out.
And to answer your first question: "Yes" I have thought outside of the box, that is why I am questioning you. I feel that you are thinking so INSIDE of the box, that you're literally thinking of putting a tank inside of a TANK!
If I hurt your feelings, then I apologize, continue with your experiment; you never know, you could start a whole new trend. I was just trying to help you open you mind just a bit more. Good luck, Sir!