(4) If the hardfork occurs, your coins will be safe as long as you do not transact until it has
been shown to be safe. You will have the same amount of coins on both chains, both
associated with your single privatekey. It is best for noobs to wait and hold their coins until
the community and devs determine it is safe to move and how to move if there are any
special precautions.
Indeed, and the only way to distinguish transactions between the two chains, is to mix with coins mined on one fork only. Otherwise, your signature is valid on both chains and your transaction will happen in both coins.