A:AnswerIt does work with Windows Ink. You may have to upgrade to the latest Windows 10 though. It comes with the "Anniversary Update" and later. And would be more useful with the latest versions of Office.
A:AnswerIt should be about the same price now. My take is that it's harder to engineer a more portable laptop (less space and weight to work with). The display might be a little cheaper for HP, but packing the same capability into an Ultrabook isn't easy.
A:AnswerIt is good with some limitations because of the N-trig technology HP uses. Mainly pressure sensitivity is lesser than in a WACOM product. Unless you're a pro artist, I would think that it is a pretty capable product to use with Photoshop. Ticktakashi.com has a good write up on the differences between the two technologies for active pens.
A:AnswerI had the exact same issue. I bought a Wacom Bamboo Ink stylus and find it works great. Just pay attention to the compatibility instructions. There are two modes, and the stylus changes by holding both buttons simultaneously.After doing that, it paired flawlessly.