Okay, so this is how it is now. I've tweaked around with the limit screws, and the tension screw, and now i have this problem. When i am on the lowest gear (biggest sprocket), and i shift to the second gear, it will not shift. i have to shift twice before it will get on the next sprocket. from there, the gear will generally shift smoothly , until around the last gears, where the ring will jump over a gear to get to where the chain should be. the derailleur seems to be in good shape. Should I keep tweaking the limit screws, or is there something else that will fix this?
And no, it doesn't look like the cable housing is gummed up, but i'll check that once we have the water outside running again (its still half-winter up here)