I assume the long power-on pause is due to the BIOS silently checking RAM, with the side effect of giving the disks ample time to spin up.
Most likely. I have an old Supermicro board (Dual Athlon MP) that's being retired from frontline service and it has a long delay from when you power it up to when it shows the POST screen. Swapping the 4GB of ECC RAM for a single non-ECC stick greatly speeds that process up so I assume there's some sort of tests it runs that can take a while.