Originally Posted by 747-444

I am new to US Airways and did a browse over their website with little success.

I am curious as to how long miles are valid for? Is there a difference between flown miles and bought miles validity?

If I have miles in the account and don't fly for a period and then opt to buy 1000 will that extend the validity of the existing miles in my account?

How difficult is redemption on United from AUS - US generally?