throwaway84356

Yes but you will soon give up once that value hits a mixer/laundry, or an exchange hot wallet. No shortage of either.

Yes, you could cut it up into new keys, but there is still much data leaked. Taint analysis, change address balances, and the fact your holding addrs don't have 100s of tx's and thus are not an exchange hot wallet is a give away.

Your bank wire doesn't leak the balance of your account to the recipient. It is a new and unique problem with some cryptocurrencies. Of course, we have already proposed solutions to problem this with ring signatures, stealth addresses, 'coinjoin', 'zerocash', 'TITAN', etc.

No, you don't want to give away the priv keys, as someone may transmit a future transaction you could claim with it. Simply signing a message would be sufficient. Don't reuse the 'k' value with your ecdsa sig!