Ok, glad some of that was helpful to you.
To answer your questions, I'd say:
1) It's probably ok to let him settle himself to sleep, 30 minutes is a bit long, but if he's happy and enjoying some quiet independent time, then it shouldn't be a problem. My DD usually takes about 15 minutes of quiet laying by herself before falling asleep. I've also learned a critical mistake: just because they wake up doesn't mean they're ready to be "up". If he wakes up mid-nap, but isn't doing a 'real' cry, then leave him for a bit to see if he'll re-settle himself. I learned the hard way that I was taking her out of the crib too early and if left alone for a bit, she'd put herself back to sleep. The key here is knowing the difference between a real cry, a mantra cry, or of course, hopefully he just wakes no crying at all!
2) The 4 Hour EASY doesn't have to be totally set by the clock, so if he eats at 7am, but you genuinely notice he's hungry again at 10:45am, then feed him. But generally, if he woke from his nap at 9:20, then you'd spend 1-1.5 hours of activity time: tummy time, exersaucer, walk in stroller or snugli, this might also be a good time to run around and do errands. Personally, I'd try to distract him until close to the next time to eat, but of course, be willing to feed if he's giving you clear signs.
3) So it looks like the first A time was 7-8:15am, one hour and fifteen, with a long wind down. Maybe try the next one for 1.5-1.75 hours, but plan on some time for him to just be in the crib included in that A time.
A few things pop out for me:
-rocking may starting to be a prop if you find you have to rock him that long... I'd work towards more opportunities to do what he did today: quietly put himself to sleep.
-if he's too big for a swaddle, I'd suggest a sleep sack/sleeping bag. Keeps them nice and cozy and feeling secure without limiting movement.
good luck
Jana