Imported Private key on to PC and now I see coins that 1 and 2 pc mined from the blocks
want to ask why do I need to export import wallet? (when I import private key from 1 pc to pc 2 it saying that wallet already exists)
is it enough to have private key, for not loosing your coins, or I need also backup wallet and why function export import needed for wallet?
Yes your private key is what you use to be able to access coins you mined with the key selected.
If both PCs have the same private key then all coins mined by both machines are available to any pc with that private key.