a) This was available from the launch of the 2IS, however it was a very rare option.
b) The multimedia option with the reversing camera was available on all 2IS models again from launch. This gave you guidelines when reversing and also some kind of parallel parking lines, although I’m not entirely sure how these worked as side cameras were never an option. No IS model came with forward guidance as a front camera was never an option either.
c) No IS model was ever fitted with full parking assist. I think the only model in the Lexus range to have this feature was the LS, although I’m not entirely sure which generation this was fitted to. Possibly the 3rd Gen model. I’m sure someone with more knowledge will come along soon.
We had an IS 250 for 8 years and it was never a difficult car to park with the reversing camera and dipping wing mirrors on the SE-L model.