Ok, you want to create a website that will basically do these things, but will keep the private key on its database, giving it to the person when they arrive to grab it?
Yeah, that may work. I think it is a solid value proposition, but there's the problem of people trusting you to hold their lumens (the lumens they're trying to send). Well, that problem exists everywhere. There's the risk of you deciding to close the site while lumen transfers are still pending and all that.
Maybe you could do some app that will do the steps I mentioned all on the client-side with Javascript (and host the code on GitHub Pages, for example, so everyone can believe). The generated private key would then be "encoded" in a readable format, like a sequence of words (see http://www.spammimic.com/ -- I'm not suggesting that, it is ugly, but as inspiration it is valid) plus a password (which will somehow simmetrically encrypt the key for safety).
The encoded private key (or, well, it could just be the raw output of encrypting the private key with the password) would then be printed or turned into a card and the person could give it to anyone else, along with the password.
Despite having a link to your site the card could also have instructions for manual deciphering of the keys.
(I'm just rumbling here, you don't have to take me serious.)
