1 - You should hear the fuel pump prime, but it will be a quick buzz/whine not a rattle. You will also hear the exhaust valve self test, that could rattle if there is a problem.
2 - Sounds like an issue with the ram air, either something is not connected properly or you have a sensor not functioning correctly.
3 - I have heard complaints of the 636 being loud, someone that has heard a few can tell you if the noise is normal.
4 - IIRC, the warranty is transferable but there is a process you need to go through. I can look into it if you need but your best bet is to go to the local dealer you plan on using for service. The thing to remember about warranty is that it is there to protect you against a manufacturing defect. If the problems you are experiencing are the result of abuse, improper maintenance, or crash damage...they won't be covered under warranty.
5 - Welcome to the board.
Rarely is the question stupid, but sometimes the answer is
you need to run everything you read online through your own personal BS meter to determine if it makes sense to you.