1. "Does the drive need to be formatted?" All new drives need to have partition(s) created and formatted before use.
2. "If so, how do I do that?" That depends. Seeing as you are trying to install Linux, you can do so during the installation process.
3. "Do most newer mother boards support scsi controllers and scsi drives?" As with most other add-on devices all motherboards that have a free PCI slot can have a SCSI contoller added on.
4. "What is a "SCSI input command"?" With SCSI, your system only tells the device what to do (input command) and the device hadles the request. Multiple commands can be sent to the device and be queued. Unlike PATA (Parallel ATA) HDDs, your system had to do all the work, hence the overhead to your CPU during large read/write operations.
5. "Time-out failure while waiting for SCSI input command. Am I suppose to type a command?" There is nothing that you can do. This indicates that an input command has been sent to the device but no reply has be received. This might indicate that the device is faulty; bad sectors etc that take too long to process and time-out.