You do not need to raid up the swap space. You can if you want to – but the risk of loss if a swap disk dies is negligible.
If you insist on a separate /boot partition, then you should RAID 1 it and span it across every single drive in the machine.
REMEMBER: After the installation and you’ve logged in the first time? Manually install grub on all the other drives.
That’s not something software raid will actually touch, and everyone forgets to do it. If the boot disk dies you will not have a bootable machine unless you do this step – and then you can boot from any disk in the machine.