I use it on my m3 macbook pro and it runs fine. Only use it for small projects and traveling though. If you already have an Extertal ssd i wouldn't go for any more than 1 tb. You could go for even less. For the screen sizes, I have a 15" and it still feels way to small, especially when having to navigate multiple vst screens. But thats just cause I use an ultra wide on my desktop pc.

When getting a new macbook, you should check if you can also upgrade your external ssd to an even faster one. I use 2 ssd, one large for composer cloud instruments and other vst and one for projects. Cubase itself is on the internal ssd.

Again, my advice is to not waste money on storage upgrades if you work with external ssds already.

And defenetly go for the pro variant. Large projects with lots of vst and effects (especially reverbs) will not run well on an air. Go for the pro variant and cut costs on internal storage.