Hi, I have answers to both questions!

1. (Random movements) - You can choose any action from the hundreds of different actions in the list:
Step 1: Go to prepare-->actions and click on any action box.
Step 2: Use the sub-menus on the left side of the little window that pops up to select the theme of your action, then choose any action from the right side of it.

2. You can set idle modes with the drop down at the bottom of the actions window.

3. To get them all doing the same action at once, animate actions then position the actions in the same place on the timeline.

If you have any more questions, make sure you've checked the tutorials first, they are essential for beginners.

http://www.muvizu.com/Tutorials