This. If you save all wallet.dat files on any bitcoin clients that you use for transactions, you'll be fine. Don't be scared off by someone using the bitcoin

This. If you save all wallet.dat files on any bitcoin clients that you use for transactions, you'll be fine. Don't be scared off by someone using the bitcoin client in a non-standard, unapproved way (and as long as you use the GUI and not the command line interface, you'll not have to worry about that).