About Minoxidil. Is it OK to shave during this process?

You can shave while using minoxidil, but you should do it before you apply minoxidil to your face.  Otherwise you would be washing the medication off.

If you wish, you can shave your head and then apply the minoxidil directly on the scalp.  It only works on the scalp anyway

Yes you can use minoxidil and shave. Minoxidil promotes blood flow to the area it is applied. Of course make sure the minoxidil has completely been dissolved into the skin so it doesn’t get washed off.