OK Hold on a minute!!! First part of the discussion you stated that you had no more shims to take out and your tire were wearing poorly, second part you stated that the INSIDE of the tires were wearing
I must be confused on this but I would think if you removed shims the wheel tends to tilt in and if you add shims the wheel should tilt out. Time you take her over to the "Linement Shop" and have them take "A Look See"