Very nice! Looks like 10" to me. I can't tell if it has a crush washer, but they are a no-go for a Halo. Peel washers only.
I like 11.5" in 5.56, and currently have a LW-barrel Commando clone. I also plan to build a MK18 Mod 1 clone, for no real reason.
9mm can be hard on lowers, especially if your hammer pin cracks in the middle. Google "9mm ramped bolt" and read all about it. The KNS pins are a good idea for that, but a ramped bolt is more important.
I've not heard of 22LR being hard on a lower in any way. It can be difficult to get/keep them running in auto, but usually RR setups are the easiest to tune. You generally have to experiment with spring weights/lengths/tension, and adjust any anti-bounce friction piece(s) your kit may have. Once it's tuned, it's usually just for that specific ammo. CCI mini-mags function the best in my experience, though obviously not the cheapest.
As far as stance and recoil, none of those setups have any recoil really. I like to groucho walk aka duck walk, cuz I'm tacticool like that.
Be sure your mags are clean. They may be now, but won't stay that way from suppressed 5.56 shooting. You'll have to clean, well,
everything more frequently. I'd get a piston setup if I actually had the time/money to shoot a lot. I was eyeballing a Sig 516 upper. "Da $" would buy a HK416 upper and swap for Geissele rail to be like Delta.
Go ahead and get that improved feed tray for your Shrike, if you haven't already.
When you add a can, it increases the cyclic rate. You will have to tune to get it cycling/running just right using different weight buffers and possibly springs. I like to use standard OEM components whenever practical, especially on consumables such as springs. You'll want to ensure it runs like a top suppressed and not, unless you only plan to do 1. (Many do.)
Swapping caliber uppers will mean a buffer swap usually.
The sky's pretty much the limit...
Don't ever get a 4-position burst kit. You'll want your money back.
Enjoy!