aardvark, if you must work alone, the ***-along will have to do. If you have someone who could work with you, tie up high on the tree, before you dig, and be ready to pull with a truck, making sure that you have tied up high enough that you won't hit the truck when the tree comes down.
I haven't found any better way to handle the roots than to cut out further, where they're the weakest, and work in.
The pines I've been taking out have been so huge that the tap root is as far down again as I have already dug with my 6.5' backhoe, so I usually dig as far down as possible, wash off as much dirt as I can, and then cut off about 4' of the stump and fill in the hole. I know that eventually the stump will rot and maybe leave a depression on the surface, but it's a whole lot better than fighting with another 6' of tap root.
Why, I haven't even been able to wobble some of them after digging all the way down, all the way around! These trees were all about 80' to 100' tall when felled.
If the trees I have left to take out weren't so close to the house, I'd tie on, dig deep, and pull them over. Scared of that since they're all within striking distance of either one or the other of my houses. John