I would also like something very similar
But if we're going the bulky way, I think it's best to stick with quad core CPUs. If ULV units advance enough to get sufficient benchmark scores, then what's the point in making it bulkier and heavier if all those thin&light laptops/tablets can do the same? On the other hand, if you make it thick anyway, then why not put the best we have? A recent quad core will always be better than a recent dual core, let's agree on that.
About the other specs - I think 17" would be way too much for a convertible, and 15" is already borderline too big. I think 13" is the perfect size for it, 14" is good, 15" is becoming a bit too big. It has to be usable not only as a laptop but also as a tablet, and it's difficult to use such a bit tablet.
Weight could be a bit lower, I think we should aim for 2kg.
The GPU is a tricky question. I think it should have Thunderbolt 3 for external graphics (because desktop graphics cards will always be more powerful than mobile ones), but also at least half-decent internal graphics. Maybe Intel Iris? But that is only possible with i7 processors AFAIK, so no i3 or i5. GeForce GT940M is the best option after that, IMO.
And then we come to battery life... For my needs it should hold through 2 consecutive lectures, which is almost 4h, at least with the GPU disabled, and still have some juice left after that. Lenovo Y700 seems to be able to do this when browsing the web and taking notes (light usage), I think it could be improved by adding a bigger battery (which is quite small btw) in favor of a weaker GPU, and also choosing a more efficient screen like AMOLED or whatever is the most efficient nowadays
Oh, I would also prefer fast charging, maybe 100W. All-day battery life isn't possible, so let's at least have the possibility to quickly recharge when it runs out without wasting any time.
Now we come to the price point. I think $1500 is the absolute maximum that could be charged for a laptop/tablet with these specs (I mean the top model, with i7, 16GB of RAM and 512GB SSD).
I also think we could use an HDD alongside an SSD. Not an SSHD, but a separate 2.5" HDD and M.2 or 2.5" (because that's cheaper) SSD. But that would waste quite a lot of space, so we would need to check if the savings are worth it.