I want to know is it safe to run two or more programs at once. Has anyone try/done this before and did you get frozen?

For example, you run "Majin Score Sender" using a proxy in one of your shell and at the time you also run the "Money Tree Killer" program using a different proxy on an different shell?

or

You run "Majin Score Sender" with a proxy in one of your shell account and the "Altador Cup Score Senders [Side-Games]" program with a different proxy on your main?