I have looked a bit into the whole NHR thing. I would not do it. There is so much uncertainty associated to it (CFC rules, anti-avoidance rules etc.), there is the limited time frame, but most of all, it seems like Portuguese bureaucracy is an absolute NIGHTMARE. Talk to some Portuguese people, they will tell you it's hell on earth.
What good is it if a structure might work in theory (or maybe not, depending on what the tax office decides later), when you can't get an advance ruling (because they don't look at hypothetical cases), when you can't do anything without a lawyer etc.︀ etc.
You'll want very clear, established rules, with many precedents, not some complicated structure with︁ lots of ifs and buts.