Grub2 can boot from a Raid0, it is a matter of adding the parameter when doing install-grub2, it also supports multiply levels of LUKS (again on such parameter add the string for luks).
I had tested it on a virtual machine... my grub.cfg file is inside:
Ext4 over a LUKS over a Raid 0 of 3 HDDs, each one over its own LUKS.
At boot i must enter LUKS key for each disk, then LUKS key for Raid 0.
I also use different algorithms, etc on each LUKS.
It was just a 'concept' test, but it worked. It also works with grub.cfg inside a LVM, and also having a long mixed chain of LVM, Raid, LUKS...
Grub2 was manually installed (only using grub2-install) and grub.cfg was manually created... i hate all that Grub2 stuff that let a script to create grub.cfg, specially 'grub2-mkconfig' (i avoid using it), i preffer to write my own grub.cfg file by my own.
Yes, i tend to use to bootloaders in chain... main one, the one i create grub.cfg manually, then i choose what to boot, Windows X, Y, Z ... Linux A, B, C, etc... and let each Linux manage its own bootloader as it wants but not letting any OS touch the main bootloader... isolating each OS.
For such i did a lot of tests on a virtual machine, some as proof of concept, some for benchmark, some to take knownledge, etc., prior to do it on my hardware.
My main URL as a base point to start, was reading this:
It explains how to install Grub2 under LVM under LUKS, etc. and have /boot inside LVM+LUKS, etc.