Don't worry about the fan kicking in when you are stood still with the engine running, it's doing it's job. Also regarding tyre pressure I tend to run at 36 psi all round. Have a look at Euromasters tyre for getting a Nitrogen inflation, tyres run cooler and hold pressure a lot better. As you live in Leeds, check out the newly formed Yorkshire section of Volvo owners. Pop along to a meet and have a chat.
P.S. If you have a 1.9 tdi xc90 you,ve been sold a pup..