Reloder 22 is a great powder for the .243, and I bet that it would be perfectly suitable for the .243AI. I use 100 grain bullets in mine and get 3100 fps with those bullets. I've only shot one deer with it so far and it wasn't a bang-flop, but he wandered off about 50 yards and started blowing pink foam out his nose. I'm perfectly happy with that performance.
The stagger feed vs center feed is a perfectly understandable confusion. Savage changed the design of the bottom metal a couple of years ago and changed the magazine design, along with the action bolt spacing. It's easy to see when you know the difference, but I can see that it would be confusing to someone not familiar with the rifle. They're all push feed, but the newer magazines are center feed, the older ones are stagger feed. Of our Savages (seven in the family), three are center feed, four are stagger feed.
What's the twist of that barrel? I've got the standard 9.25 twist on my .243 and at 100 yards I'm starting to see keyholing on the 105 A-Max. Bad keyholing on the 107 Sierra MK. So, I've stayed down at 100 grains for now. When I rebarrel, I'm going with a 7 or 8 twist to see if I can use those lovely, long bullets.
But, nice rifle. I'm sure you'll be happy with it. And yes, Reloder 22 is an excellent powder for that caliber.