Wonder if the NG+ witcher gear is at fixed level or scaled using my starting level as offset? Would like to start NG+ with LVL69.

That sounds like a high level to me. I NG+'d at level 39 and I had finished the game on hardest while stopping to do most everything for trophies.

So far I've noticed that I need to buy all the diagrams and such again and that the gear has a higher level usage so I'm guessing it scales up but you have to make it all again.

my only fear is that the reqs will be like 20 levels below mine, so never really useful

I would think the stats would be better but not extremely so, while having a higher level requirement. But honestly I don't know enough about how the scaling works in this game :(