Auto Insurance Claims: Auto Accident, accident 1, insurance card

Hello, I have been recently involved in a 3 vehicle accident.  A young driver rear ended my self and another driver. I have a police report where the driver that rear ended us is obviously at fault and it is stated on the police report.  I had no car insurance at the moment of the accident.  
1) Is my lack of unsurance an obstacle that his insurance company can use against me in order to avoid my claim?
2) Is his insurance company legally responsable to cover all damagaes caused by his fault in the accident?
3) What can I do if the driver at fault does not have insurance? (the policy number is on the report but I remember seeing the driver at faults expired insurance card, although he swore to us and the cop that it was just the old card, that the new one was home)

Thank you

Generally speaking, the fact that you were uninsured does not lessen that other party's liability.  If he is insured, then his insurance company is responsible for the damages.  If he has no insurance, then you will have to pursue him individually.
Do remember that a police report alone does not determine liability.  It is only a document summarizing what the police observed at the scene.  The insurance company has the right and the duty to complete their own investigation before liability will be accepted.
Good luck!