u/LR_Defender_4x4

Hi, recently I bought Volvo V70XC (manual) make year 2001 with 370k kilometers on odometr. It has 2.4 T gasoline engine (147kW). I want to do some maintenance, such as timing belt, fluid change, etc. I know that common problem is that PCV is not working, I have already fixed it. So I have some questions:

What is best to do / check on this car so that it will last long?

Should I, or is it even possible to change oil in visco coupling?

Thanks. (Also sorry for my english)