I bought them but did not install them, becuase I forgot! If your planning to use them, make sure you remove the rubber caps that cover the holes before you install the bumper.
I have a 2011 LX but I'm watching for a 2016 LC. There are some nuances between model years but I really don't know of any deal breakers on a specific model year. Obviously better if the things mentioned have been addressed before finding out by accident they haven't!
Do the seat heaters work? In 'most' cases, it's the ecu module that controls the heat and vent located under each seat. You can either buy new or buy one for a similar year LS and retrofit. Several older threads on this as well. Regarding the sensors, do the rear work? If not, I would...
I just redid mine at 165K. Didn't do the analysis on if they were needed / not needed just felt like it was time. Globes from Japan for ~$600. Fluid was ~$150. My issue was getting the globes off on my DIY 'attempt.' The videos make it look easy, mine were not easy to remove.
I can't comment on price but I would put $3,000 in the 'just in case' fund. You can somewhat figure out what the outstanding issues are based on what's already done / not done and proactively go after those items along the way.
I would research ... there are places online that specialize in this approach (and parts) wise ... depending on what you want to do, stock height, leveled out, etc. Not sure if your an AI person or not but Google Gemini was a big help on this for me. I don't know your market but I'd get...
It's very hard to see the fluid level if you dont know what to look for. For entertainment value and maybe a fix, I would top off the system and re-assess. There are youtubes on procedures to clear the codes.
I went through this a few months ago. My cost was basically the globes and fluid so that's the direction I went. From what you are describing I would find a shop that can advise on fixing or replacing. Lots of good options out there at various price points from about $1,000 - lots more!