slownsteady, the previous owners dug into the hill, and then build the house's rear supports right against the wall of exposed earth created from the dig ... then built a retaining wall that was attached to the building's supports, with earth pressing against the retaining wall. that decision plus the single-block columns were bad ones, to say the least! but that just pushed the rear supports forward, which brought the house and all other supports forward too, at least 6 inches... so the movement of the front columns occurred at the top, while their bases never moved, hence the leaning forward.
as for the rest of the discussion, I'm strongly considering taking the advice to install wooden posts with diagonal braces. this raises a few questions. Can I really just drill into the existing concrete and then insert a post saddle? aren't they usually put into wet cement.. and also, are those really strong enough to support a house, and not just a deck? for example do you think the basic post saddle would have been used in the house photos that Inspector posted, or would it have been a more heavy-duty, deeper-sunk saddle/anchor.
also, keep in mind that the 'footings' are only in place on the sides of the house, and only between the front and middle columns. the rest of the columns are just cement and rebar-filled blocks sunk about 4 ft deep. as for cutting into the existing columns and using their bases as supports for post saddles, do you really think I can cut through the rebar, and then insert a saddle? I guess I could try, but it might be cleaner/stronger to completely remove the post and pour new cement footings... especially since even the bases are leaning a bit. so I'm guessing I will install temporary wooden posts on the existing footings, combined with jack posts in other places, and then in the spring, undertake the larger operation of replacing the columns one by one... thanks for everyone's continued interest.