Apple TV box has the best streaming quality over everything. I would keep using the dedicated box.
Get an M1 then wait at least another two or three years until the architecture has advanced again. I can’t stress how fast M1 is.
Might need a repaste.
Even a base M1 air/pro would suffice for that usage. If you want to use it for 5+ years, go for the base M2 or M3. But to be honest even the base M1 is so overpowered, it’ll be incredible for what you want.
They’re all fantastic and trust me when I say this that depending on your workload, you’re probably purchasing an overkill of a product.
If it’s everyday usage, I would only even go for the M1. Everything you’ve stated is overkill for general university purposes. Hell my M1 Pro 16inch was overkill and I was on a film/photo/media course.
But if you wanna spend, go M3. It’s the newest architecture and is insane bang for your buck.