Hi & Welcome
Rust on the sill's is something you need to check for , wel really check for rust / rot all round .
My few worries:
1. A/C doesn't work as of right now, he's supposedly going to fix it.
2. !!!!! White dashboard, can it be genuine? I haven't seen a 2003 alfa with a white dash. !!!!! . Yes they came with white but its silver really
3. Airbag light ON, but i've read about how to fix that issue. ..Yes fairly easy fix in most cases
4. Coolant tube,why is it so damn dirty? ..This just happens it doesnt look like its boiled over its just dirty
5. In the front, the cap ,from which you can pop the towing hook has some sort of glue on it,as if it has been opened before,which would mean it has been towed. ... The caps do fall off so get glued in, but you cant tell if towed or not so cant help much there.. but the threads tend to rust so you can look at the thread and see if its clean that may give a good idea if its been towed
Service history if its been poorly looked after walk away unless silly cheap and your able to repair things.
Best rule to stick by is .. If in doubt walk away there is plenty of cars out there
Will check for rust on the floorpan for sure. Read that it's most vulnerable there and on the mounts for the front bumper,both will be thoughroughly checked.
The silver dashboard had me worried it had been in an accident, you definitely eliminated that doubt. Will still check for the usual places,which might indicate a crash at some point of the vehicle's life.
From my understanding, it's alright for the tube to be dirty? A person I know said it means it's been poorly taken care off, or something simular. Never would I go to a car with a perfect engine bay, definitely hiding something.
Will check the thread, if it's rusted, my guess it hasn't been towed.
Car is priced 1600 EUR with replaced suspension a few months ago. Service history is non-existant in my country, the owner kept all his receipts, but those before him, what they have done to the car I have no clue.
Forgot the add, 186 000 km. Will service it with Selenia TurboDiesel 10W40 and quality filters, hope it's not necessary to change the timing right away, steep prices .