I'm new to Bitcoin, and I'd like to bounce some ideas for a thin client for Bitcoin hardware wallets. I may have misunderstood some fundementals.

I'm considering hardware devices, which would hold addresses and private keys. They would be used to securely store the private keys, and have an Ethernet connection for communicating with the P2P bitcoin network.

The wallet should be able to display the balances of the addresses, and spend bitcoins for the addresses. It has no ambition to verify transactions from other nodes on the network.

I'm thinking the client won't need to store much blockchain information except unspent inputs for its' own addresses. It might track the last six verified blocks in the block-chain and assume that that means that there is no fork. If the keypairs are generated on the device, it will know that there are no transactions in the blockchain for the addresses before they were created.

It will listen for 'deposits' to its address, update the balance, and remember the unspent outputs in order to be able to refer to them in output transactions.

I'm thinking this will let me make a thin client without needing a separate server.

Did I miss something? Is it immoral ;-) to connect to the Bitcoin network without validating third party transactions? Any other think-o's?

Thanks!