Just reading this thread but... oh dear the Gmail selection bug is back? I recall just permanently switching to the simple interface because I got upset of how often the Gmail client would bug up badly every so often (by that I mean like every week or two). I had forgotten about it by now because of how long ago I had switched (the simple interface is much less buggy, even if it lacks some features). Ugh.
So: avoid some of the new features for now (you have to go and try for now), avoid messing with the DOM (that tends to be a big offender when you update it) and avoid having more scripting than really needed. At least this will keep things mostly in check.
Cortana and XBox integration are signatures features of Windows 10. It's not clear to me why on Earth they would make those uninstallable.
The people who want these off are mostly people who are upgrading from an older version. They want the ability to run newer software and keep security patches and such (which means they eventually have to update) but they don't really care about the new stuff usually (especially stuff that can be seen as getting in the way instead of just being there as an extra feature at the side).
Not surprising, when you consider Microsoft and Apple are probably the two who would less want non-restricted technologies to proliferate (remember that the whole deal here is that the MPEG codecs are patented while the OGG codecs aren't, meaning that anybody implementing the former legally would have to pay license fees and be required to implement any DRM the companies want while the latter wouldn't).