Are these pre-printed with a generic Wallet Address and or pre-loaded with funds, or would the purchaser have to print and or load with funds themselves?

What would stop someone loading up a 1/10th BTC wallet address with more than the amount stated?

Also, how unique are the tamper-proof stickers?  Why I ask someone could purchase their own tamper-proof stickers and reapply over the secret key part of the note.