Once I used that tool to do the split then what shall I do next with BCC?
That will depends on you if you hold it it or you will sale it.
Bitcoin cash is a fork of Bitcoin when split happens in August 1.
Bitcoin Cash team dont support segwit so they develop their own.
Which Exchanges support BCC?
ViaBTC claimed that they support Bitcoin cash and they will listed Bitcoin cash to their own exchange.As for now i didnt heard that some exchanges support Bitcoin cash.
What august date is safe/best to send BCC to an exchange so I can dump it and get free cash?
I dont know