Not the OP, but coming from an adult education perspective, the suggested number of things that an adult can remember at one time is 7, + or - 2. It's called Miller's Law.
Basically the number of things an adult can keep in Short Term memory.
Okay, but those things were about
working memory. As in, you're having to pick up new things and memorize them on demand, holding all of them purely in your head at the same time, which you weren't familiar with prior to being told.
That's the stuff you can only have about 7 of in your head at one time before things start to break down. And, yeah, if you had to memorize even three separate spells and then never look at the written stuff again, that would be a problem!
But when it's stuff you can be familiar with because you've seen it a thousand times, it's not in
working memory anymore. It's written down, so the details aren't directly relevant, only the tag is--and that gets lodged in long-term memory, which can hold a hell of a lot more.
Hence why it matters that, for example, two of your powers are At-Wills that essentially never change (other than getting more powerful at Epic.) And that more than half your powers are utilities once you get to high level, because a lot of those are pretty specific. Finally, with many powers being Encounter or Daily, while you might have a dozen at the
start of a day or fight, the numbers whittle down over time.
In other words, yeah, there are a fair few here! But it's dicey to say that this is somehow massively overwhelming. It does expect that players will learn and remember their core actions. Every game has expectations of that nature. If a player can't remember their core abilities, they're going to struggle to play any tabletop game with mechanics beyond "ask the GM."