4.
Install the motherboard first. The drives will have wiring harness to connect to the motherboard.
Because you might drop the drives on your motherboard while installing.
Drives are linked by cables called SATA cables, these send data through the motherboard
Yes it does. 6 xSATA 3 Gb/s
Everything is connected to the motherboard. Everything other than hard drives and disc drives would be directly on the motherboard.
Case, Power Supply and Motherboard The case must support the form factor of the motherboard, and the motherboard must support the CPU socket type for any given CPU.
SATA, or serial advanced technology attachment, connects the motherboard to hard drives and optical drives. This cable is inserted into the SATA slot on the motherboard.
You should be able to as long as the motherboard will support that many hard drives.
The most commonly used technology standard for hard drives to interface with the motherboard today is SATA (Serial ATA). SATA provides a high-speed connection for data transfer between the drive and the motherboard, supporting various drive types such as HDDs and SSDs. Another emerging standard is NVMe (Non-Volatile Memory Express), which is used primarily for SSDs connected via the PCIe interface, offering even faster data transfer rates than SATA.
It wouldn't be a SATA motherboard if you couldn't connect SATA drives to it.
Motherboard
I usually put in the motherboard first. After the motherboard you put in the CPU & then the CPU cooler which is rather difficult to install if there are other components (like hard drives) on the way. By putting in the motherboard first everything else is much easier.