I have to go turn a steak over in about 5 minutes (yeah, life is tough) so I will give some general answers
You can buy old guns without one.
It's a license for your personal collection. You're not a dealer in old guns, you have an FFL to build up your own collection. You have to keep a bound book, and it can be audited but it's not to run a business
There is no 'phone call' with a C&R when you buy using it. Both parties are licensed as collectors for purposes of the transaction. Swap info, record it in your book, pay the man, walk away with the firearm
Some deals can be had using the C&R