1) Yes if you have an SSD or top end HDD
2) You have to go back to your BIOS and reselect your main drive as your boot drive because when you switch ports the BIOS chooses the next boot drive according to boot priority. So resetting the BOOT options and have your main driver as the primary boo drive would fix that and make sure you save the settings
3) Yes the Sata II and III cables are the same so no need to buy new ones.
I hope this helps