@Henrycase
I have a very good friend who is far more technical than I am. He used to code for Amiga systems funny enough, mostly touchscreen based point of sale systems. Now he's freelance but the bulk of his work comes from a system he wrote for transferring large amounts of securely encrypted data. It's quite well known apparently.
Anyway the point is that about 11 years ago that we had a long talk about something very similar to you idea. Particularly regarding the blurring of hardware and software boundaries. It was all just theory and "this is the direction I would like to see things going" kind of chat but I've never quite looked at hardware the same way since.
I heartily agree that a true Amiga revival will not ever be an Amiga revival as such but rather a revival of innovation, the Amiga spirit if you will. Your "from the ground upwards" kind of thinking is just what we need.
The big question of course is not so much if it can be done, it is more to do with if it can be done at the right price but please, don't let that put you off trying. I guess you'll work that out as you go along.
Good luck, I hope something comes from this.