1. If I brought back 4 sprinkler valves would US customs think im illegally importing them to NZ and selling them off? I know if you import too much of the same item, customs get suspicious and think your importing and then selling them off and they take and destroy them.

2. Would a bunch of galvanized pipe and/or fittings look to suspicious in my suitcase? I could see how they would think it looks like a bomb.
Are there any rules/laws against it?
3. Do McMaster have a physical store like on the street like any other normal store? Because I wont have time to order online there but if I came accross a McMaster store I could drop in.