Avatar's appearance while logged out, etc

Hi, I'm new. I have some questions about gestures etc:

1) Does my avatar stay visible in SL while I'm logged out? If so, what pose does it adopt? (I suppose it might be "away" but I obviously have no way of knowing)... can I change this so my avatar does something else while I'm logged out?
2) while I'm not doing anything, my avatar makes some small movements: shifting weight, blinking etc... are these 'resting' movements modifiable?

Thanks.

Your avatar dissapears when you log off and you can use an animation overrider to override the default movements. The overrider itself is usually very cheap or free but you have to usually buy the animations separately.