Just for the record it would be nice to know if your rear wheel drive is working.
Would be possible to get all four wheels off the ground to check?
Any chance you could check to see what happens when both front wheels are off the ground?
Yes that does sound like there is a problem. With trans in park and one front wheel off the ground it should not move. It might be a stripped pinion
You are not alone as I think my front diff is on the way out. There is an awlful lot of open backlash in my front diff that gets bigger day by day.