Some questions about approval process

Could you help me?

Is it can be realized as follows in the approval process:

1. PO price than the shopping cart within margin 5% to add manager approval
2. Current approve is absent based on 2 weeks auto go to the backup person. How to setup back.
3. Reject the shop cart and back to the requester. If the money/ cost center /category doesn't change need to go to the next step without approved just to the rejected person.

If yes, how to configure it? Thank you very much.