Only 13"? that would be just a slight increase, I can't imagine that would really matter for most. Than I would suggest to make a big version from 14/15" that would have a much better impact than going to 13". And the upside is that those who want ultra portability don't need to handle the extra weight and size from that 0,5" extra (which they will, I can guarantee). The extra size could even be used to accommodate a stronger CPU (the V can handle 12W, so the big version would be able to handle 15+W). I do like your idea of still having a mini display port, I don't want to carry dongles and docks all the time so useful ports shouldn't be ditched to the thunderbolt.
AMD is indeed competing greatly with intel, but at a big downside, comparing the ryzen 1700/1700X/1800X with the 7800X/7820X/7900X: they use more power on idle (important for getting battery life), they have less performance per core so I don't know if they can give the same performance/power. Leave TDP out of this, since intel and AMD have their own way of claiming TDP so that can't be really compared. The biggest upside for AMD is their pricing, the lower performance is compensated by a big price cut. They will be launching mobile CPU's, but those would need an iGPU and they probably will also have the same performance disadvantage over Intel so for the moment we can only wait and see how good or bad they are. Also I can guarantee that threadripper will not come to 2 in 1, the 8 ryzen 7 eightcores go up to 95W, that promises on the TDP for threadripper... If most 2 in 1's can't keep a 15W dual core cool, and those who try 45W quad core have a big struggle to make it not as thick and unwieldy as a laptop (and also still have thermal throttling), I can not imagine 95+W cpu without iGPU will make it.
For the pen: I can't really test that out since I use a broken surface pro which half of the time doesn't register the pen touching it or register the pen touching it when still centimeters away... But on moments that it does work, I can't really tell the 1024 pressure levels apart, so I don't see a need to quadruple that, but I guess it is for painters and such to decide on that since they have more experience on that side, most of those that I know do say that they don't really need to go above that 1024 pressure levels.