Yes, every wallet is going into the fork. And the empty wallets will be empty. And the wallets with bitcoins in them will have both BCH and BTC.
Yes, this is good strategy. To be clear, this only works if you move your bitcoins after the fork starts, not before.
oh now i understand, so only the wallet that are full after the full can claim even if they are empty afterward, it make sense now, so i don't have to move on exchange to claim right? i can calim at any time as long as my wallet hold btc after the fork? even within one year?
The "Bitcoin Cash" Coins are a copy of your existing BTC coins on the "new" BCC Blockchain. So, if you have access to your private key you can claim them as long the network is alive. You dont have to do anything now.
But, as written above - take care about your Bitcoin, when you claim your BCC.