You can check first upgrade by seeing if it has different tail lights, blinkers on side mirror and different front bar. 3rd update different in same areas again
Try polish/buff it first, it doesn't look bad in the pic. You are best taking it to chatswood to get a quote,it will vary depending on the panel/damage.
Oh I meant if it was a prestige, f sport or sports luxury, I'm certain you have leather, only the 06-08 sports had the alcantara seats. Reason I asked is because the price paid can get you the 2010+ update shape. Perhaps even the f sport with the DRL.
I think 75k included the fuel filter replacement so yeah fuel should be low. If they request dashcams be turned off then yeah, but no harm in leaving them on. I left mine on and I requested they take care going up ramps and bumps. Dashcam showed they drove the car like a 4wd, scraping my exhausts and lip (not scl). But you don't need to worry about anything else.
Yeah injector cleaner, or any other carbon cleaner. The is250 is known for carbon build up which affects performance and makes the car rough idle/low rpm. Lexus provides this service, or you can diy. I use subie upper engine cleaner and spray it in the intake inlet.
According to the owners manual, its a 'Malfunction Indicator lamp' Which indicates there is a problem somewhere in the engine electrical system or electronic throttle control system.
Unless your gas pedal doesn't work properly, it is likely the former of the two.