The noise is annoying but nothing to rush out and get fixed. My 325 was making noise for about 4 months before I finally decided to service them. I have done this job a couple dozen times and it’s not hard but you will need some not so common tools for the average toolbox. First is a 36mm open end wrench and the second is a very large Torx (cant remember the size). If you can get the fan clutch off (reverse threaded) your set, plenty of room once the fan and fan shroud are out.

As for the belt it depends on heat and time generally. I live in a cool area and my belts show cracks at around 35k or about 4 years for how much I drive. Belts don’t break like the use to, but they can slip and make noise when the ribs start to wear. So if I was to make a general statement, at 70K you are probably close to the maximum life of the belts and pulleys.