Replacing coolant parts as a safe measure

I have a 2016 that I’ve never done any maintenance to other than oil change and changing the converter and engine coolant once and replaced front break pads recently. It’s got 171k miles on it. I’d like to change coolant again and due to mileage should I have them go ahead and replace the converter water pump even though it’s currently working ok? And is there anything else I should go ahead and replace while I’m at it concerning the coolant systems? Economy being what it is I want to drive it long as I can before having to buy another. With its age I’m going to need to do a lot of upcoming maintenance, shocks, struts, rear brakes. But for now I’m concerned about the coolant systems as it can ruin the hybrid battery if the water pump goes out. I’m elderly and don’t want to get stranded. Sometimes I hear a wamp wamp noise like a bad tire which can be the water pump noise but hubby keeps telling me it’s different road pavements. Also what about caring for the generator? Also my dealership has never had anyone trained to check the viscosity of my brake fluid and they aren’t equipped to change that either. It’s terrible but I have to use independent mechanics as very few Toyota dealers are trained on the Priuses. I don’t u derstand this because there are lots of them on the road but no one seems to want to work on them. The dealer told me to leave my brake fluid alone that if it’s not leaking to not touch it. They don’t have the pressure equipment to change it. I realize this is a lot of questions in one post. But my car has been neglected. I plant to do the converter and engine fluid first. Then rear brakes, then shocks then maybe see about this brake fluid issue and then whatever else y’all suggest. My husband is elderly in bad health so we won’t be doing out own repairs. Not unless a cave man could do it.