There's a patch (I think it will be pulled in) that allows import/export of keys from/to a wallet, making what you suggested even nicer (also makes bitbills easier to redeem)
I fail to see how that's simpler (from a user perspective) than btcfn would be. Start freenet, start bitcoin, use as normal.
The whole concept of selling a wallet is simpler: you can send it via snail mail, USB stick or via morse code. It becomes independent of the medium and is quite intuitive. AND: no transaction costs
Imagine, it could even happen that at some point you sell wallets of 0.1 bc like they were discrete units.
"It costs 20 Bc"
"Ok, I'll send you 4 x 5 Bc wallets"
Untraceable and no transaction fees..