So far i have learned how to make a safe paper wallet with bootable Ubuntu. What i understand is that exchanges are very vulnerable to hacking. I have chosen Bitstamp for exchange (hope i get verified soon). I was wondering if is it safe to use that bootable os for exchange too?
This is a server-side issue, not a client-side one. Bootable Ubuntu only helps you avoid someone stole your access; can't make the site better.
To minimize risk just keep your money there for the shortest time possibile.