As a fellow engineering student, I have used several CAD programs like SolidWorks and ANSYS with a Surface Pro 3 i3 and SP4 i5, and the experience has been sub-par to put it blunt.
The reason is 12" is not that usable for those programs to begin with. It has toolbars on top and on the left, and sometimes on the right. Youd only have something like 8" to see the actual product youre designing. To make it worse, some of those programs are still not optimized for high DPI. I was forced to set lower screen resolution on my SP4. Thats two strike already, but can be easily solved with an external monitor. What cant be solved with an external monitor is the performance. It would be sufficient, you can technically do it there, but the experience is less than ideal. Panning, zooming, etc. will be a bit sluggish. Without an external monitor I would honestly pick your Acer over the Eve V or Surface for engineering programs, any day.
Ideally, Id recommend a decent desktop PC (even the one with Pentium G4560 is already faster than an i7 tablet) combined with a 24"+ monitor, thats where you can work comfortably and not limited by the technology. Let me know about your budget, we can try to make the most out of it.
Make no mistake, being able to open and make quick changes on a device as small-and-light as a Surface or Eve V is SUPER useful, but I honestly wouldnt design an entire gearbox on 12" device with low-voltage mobile CPU.
There is OneNote for iOS, its very similar to the Windows Store version of OneNote. There is a built-in Notes app, which was recently updated in iOS 11 to be on par with OneNote in term of features, but it only syncs with other iOS or Mac devices, so I dont use it. Keep in mind that the 20 ms latency that Apple advertises is only applicable with some apps. The Notes app is one of them, OneNote is not. It behaves more similarly to the older Surface Pen there.
Let me know if you have some other questions, cheers.