Help finishing off Centos 7 RAID install

I've just finished installing a new Bacula storeage server. Prior to doing the
install I did some research and ended up deciding to do the following

6x4TB drives
/boot/efi efi_fs sda1
/boot/efi_copy efi_fs sdb1
/boot xfs RAID1 sda2 sdb2
VG RAID6 all drives containing


1) The big problem with this is that it is dependant on sda for booting. I
did find an aritcle on how to set up boot loading on multiple HDD's,
including cloning /boot/efi but I now can't find it. Does anyone know of a
similar article?

2) is putting SWAP in a RAID a good idea? Will it help, will it cause