I remember watching a video of some guy who jerry-rigged the iso so he could install 7 and run it on a kaby(i think) system, but there were trade-offs like broken safe mode and perhaps some more important stuff. It's not worth it imo. If you want a 7-like experience, go with 10 Ent LTSB(LTSC) 2016. It's about as close to 7 as you can get on windows 10 without too much hassle.
Depends, on something like a laptop that's set in stone or most other OEM off the shelf pc's, your not going to get much help getting Windows 7 installed, they'll make it very difficult If your going to build a custom pc and buy your own pc parts then most motherboard manufacture's are providing Windows 7 drivers for Kaby Lake CPU's Example; I have an Asus B250x motherboard I just bought recently and Asus does have Windows 7 support for that board