Not a dumb question at all, yes I had flushed all the ink lines (I need to study this possibility to modify the maintenance tank, because with every init fill, flush lines, it must be change very often..)
About K7 and P2, it wasn't an advanced/professional comparison. I had some prints on K7 and I printed them again with P2.quad. Without relinearization. In my case, the passage between the gray seems softer in k7, but it's minimalist, and as I said, not a professional/tecnical comparison. I'm almost sure that with linearization it's imperceptible.