u put it on the inside of the jeans. should barely be visible. howevre ud still get some staining, but it wouldnt be nearly as much.
ask your tailor to take in the waist and the seat, thats what i did with my RRL's. they were a 38 and i got it taken into a 35.5-36. and they fit nicely now.
Throw in the machine in hot water and put in dryer right away after wash.
given they are rigid 501s, so it doesnt matter much, but generally u dont want to throw ur denim in the dryer because it'll soften denim
It's important to wash your jeans at least once a week. Like what I said, throw in the dryer to dry.