Yoshi will be 6 weeks old in a few days, and he's been eating crushed up pellets for almost a week now. I crushed them with a rolling pin so they were mostly dust. I just crushed up a new batch tonight, but I left the pellets a little larger, and I'm just paranoid he might choke on one. He hasn't had any issues before, as there were larger/normal sized pellets in the previous batch that he would eat just fine. I just get so nervous, seeing him roll it around in his mouth, in between grinding it with his beak. Have you guys ever had anything happen? Or am I just being paranoid?
I've never seen a parrot choke. I suppose it's possible, but I've never seen it. I've seen babies aspirate a tiny bit of formula. Usually, they need to cough and it amounts to nothing as long as it isn't a large amount. That's the closest thing to choking I've ever seen in a parrot.
I've also seen babies do the feeding response while holding solid food in their beaks and then seem to wonder why the food didn't magically travel into their crops. XD
You're doing the same thing I am: crushing pellets. It's working well for Kizzy. Her beak isn't strong enough to crush the pellets, so I'm crumbling them up. I'd keep Yoshi's small, anyway, just to be safe. Why not? As an aside, make sure he knows how to drink water. I used chicken starter crumbles as part of Kizzy's hand-feeding formula and I was shocked at how much they expanded in water. A bird eating dry pellets / crumbles will be a thirsty bird. I've seen Kizzy drink, but I remind her where the water is by picking it up and showing it to her and saying clearly, "Water." It's one of the words I've heard her say.
She isn't talking a lot, but she is throwing in an occasional "hello," "up," "fill-in-the-blank." When she goes to sleep, she starts mumbling. I'm hearing the things I say to her, only the syllables aren't clear: "Up, up! Good girl, Kizzy! You're a good girl. Be an eagle!" Every baby Amazon I've been around has done that when the vacuum cleaner is on, when music is playing or while drifting off to sleep. It's an endearing trait of baby Amazons.

P.S. Kizzy's breeder recommended cooking chicken starter crumbles in water so they would expand and using them as part of a hand-feeding formula. He recommended mixing it with Kaytee Exact and Pretty Bird Handrearing Formula. I followed his recommendations, but went one better and added Roudybush as well. That way, if there was a bad batch of formula, it would be mitigated by the other three formulas. Kizzy's breeder likes to include chicken starter because forty years of research went into finding the best formula to grow chickens to egg-laying size in a very short amount of time. Parrots aren't chickens, so he uses it as a supplement to two different hand-feeding formulas for parrots. Kizzy seemed to do well on it. She is a small blue front, but I'm positive that's due to genes. She grew really super fast, passed her final weight and started losing weight for fledging. As a light-boned, petite blue front, she is an aerodynamic wonder, fledging before she turned eight weeks old.

Yeah, I'm proud of the job I've done so far.

I'm sure Yoshi's mom will be very proud, too.