I’m searching for a somewhat affordable laptop for 2d and 3d graphics work for and alongside college.
What I’m looking for in order of importance:
good screen (color accuracy, etc.)
powerful (cpu, gpu)
touch / pen enabled screen, possibly tablet or “yoga” device
good battery life
servicability/upgradability
weight/size
My budget is 1400€ with German student rebate programs, or around 800…900 if I have to sacrifice performance and/or screen.
I’d be happy about any input/advice 
Refurbished is a bit of a risk, but a refurbished Surface Pro 2 sounds like quite the steal for it's price:
I'd be careful about who the seller is though when digging for refurbished. Also, the CPU is an i5 4200U according to the website and yet my Surface Pro 2 is an i5 4300U.
CPU and GPU aren't very powerful, I argued it was a tad overpriced at launch, although I enjoyed the tablet a lot and still do, just wish I could fix a couple of tiny scratches. Compared to any tablet at that time it was really powerful though, it isn't until recently had we seen iPads and Android tablets outperforming it, even the Tegra K1 was only tied in GPU performance roughly.
Surface Pro 3's are getting low in price as well and it has a bigger screen, Vaio Z canvas has been going up and down too wildly, right now it's too expensive for me, wish it could come back down to $1400 territory for 16 GB/512 GB PCIE SSD or better yet, $1600 for 16 GB/1 TB PCIE SSD.
The Surface Book with GPU might be what you're looking for. The Nvidia GPU will surely help for some 3D and 2D work, has a really good screen and comes with a pen.
what do you think about the Lenovo x1 yoga or P40? They both have a pen digitizer but I'm not sure about the display quality.
Oh and thanks for the suggestions so far