Thoughts on Keeping a 2004–2009 Prius Running Strong

Hi everyone, I’ve recently joined this community and I’m excited to share and learn. I own a 2007 Prius (Gen 2), and I’d love to hear your tips and experience on long-term maintenance.
A few specific questions I have:

What maintenance tasks do you recommend doing before serious trouble starts (e.g. inverter, hybrid battery, coolant, etc.)?

Which upgrades or replacements have given the best value/performance improvement for the Gen 2?

Any advice on reliable sources for OEM parts or trustworthy remanufactured components?

Thanks in advance for all the help. Looking forward to contributing to this community!