Wow, you sure did a lot of work there! I've gone the other route, and conceded victory to my live oak roots. Three huge trees around the house, so there just are tree roots everywhere. I manage to grow stuff by sinking big nursery pots into the soil and planting my shade-lovers in the pots. It takes several years for the tree roots to invade the pots, then I just take cuttings or divisions and re-pot.
Keep us posted, it's going to look really lovely! Good luck.
