every 5 or 10BTC ... use a new wallet.
i do this.
when you pay ... seller don't know if you have more than 5 or 10 BTC.
New wallet or new private key? What about a reasonable cold/hot wallet mixture? And what about online wallets so that your coins are portable?
I feel there should be a good ratio of such wallet types, I just don't know which ratio would be best.
It seems like 1-2 cold storage wallets, 1 PC hot wallet, 1 brain wallet?, 1 phone hot wallet and 1 internet hot wallet might work, but then what ratio of coins to each wallet?