Nice, I really like those pair ups of the cores to the attributes. I've never tried tying them specifically like that, so I'm interested to see how it turns out. I'm very invested in your hack already, heh, since I love OpenD6 so much and think that the system still (mostly) holds up to this day.
I haven't seen the variant with only a single d6 roll, but that seems like a good way to even out the massive discrepancies between someone rolling 1D vs 5D! And having a set number of action dice that you can use to boost it, but those also double as your action economy? This is good stuff!
Please share the pdf with me when it's at a stage your comfortable with, and good luck!