The request:   It would be useful to limit the lifetime of a bitcoin
address.

Not only useful but essential! Otherwise mobile clients can run out of RAM and have to cycle around and reuse addresses. 

Which is indeed why BIP70 has this feature. It was thought about quite some time ago. Addresses are an evolutionary dead end, they will never do everything we need them to do. If there's somewhere that's using addresses, that's somewhere we will eventually need to upgrade to use BIP70 instead.