2010 Insignia estate help

[Cliffk]

Hi all Im new to the forum and looking to be new to insignia estate ownership.

Ive found a 2010 2.0 cdti se thats been unused since the end of May consequently its dirty and the trims around the windows and roof rails have gone cloudy do we think these will clean up?

The tail gate button on the tailgate doesnt work (seller says it works occasionally but didnt work for me) the tail gate opens off the key and opens and closes off the door button, is this an easy fix?

Can the tailgate be opened manually from the outside?

It has half leather ( actually looks like material backed thin leather) and the drivers bolster is cracking, any advise on this issue I believe its quite common.

The seller says timing belt and water pump changed but cant provide a receipt, should I consider replacing the timing belt and water pump if I buy it (mileage 123000)

Sorry for all the questions but know nothing about these cars but the size and load space is perfect for me so quite intent on buying one about this age and mileage.

Any advice appreciated