Looks to me like you've pretty much got it figured out.

Single shot follower or sled will get you where you want to be.
As far as a .223 bolt head? No issues, just a regular, turned over to kick out to the open side. No ejector rod/spring sure makes short work of extracting/ejecting issues.
Fired brass stays on the bolt head till YOU pick it off.

With the .223 bolt head, nothing but the .221 Fireball barrel to deal with. You're single feeding anyway so no issues.
I started out with a 110 V (J) Series in .223 way back in the day. Swapped barrels to .221 Fireball. Been a fun ride since then.
The .221 Fireball showed me the shortcomings of the Savage actions. I've learned "a lot" since then. The "short round" didn't work in the Savage actions till you understand what's going on and you learn the "single shot" thing. After that, you can chamber just about anything.

Only suggestion would be go "zero freebore" on the chamber and start off with the lightest bullets you can get your hands on. Will be a long time before the throat wears enough to go to heavier bullets.
Best 5 shot group came out at .110" at 100 yards. And as you might guess, I LOVE MY .221 FIREBALL. Started life as a Remington XP 100 but got converted to a rifle. Might even pick up another XP Pistol in .221 Fireball.