The valve cover gasket might be debatable, but other than that it all looks legit to me.
Do the whole deal. IMHO the mechanic is NOT trying to charge you for anything other than what’s needed AND those things that are definitely prudent to do when a water pump is changed on an engine of that mileage. He’s helping you take good care of the car for in affordable steps.
The water pump is driven by the timing belt. At your mileage, once the mechanic is there it makes sense to change all the wear items associated with it. And it’s never acceptable to try to reuse a belt.