[Google Pixel 2 Questions & Answers] Rukbat:
First, as someone who spent years working on other company's databases, I can tell you from experience that the few people at Google who can access your data aren't going to be accessing it. When they're working on a database, it's not your data they're looking for, it's the reason the database isn't working that they're looking for. Once they find that they go on to the real work they're being paid for and try to catch up on the time they wasted getting the database (which may hold everyone's pictures or everyone's contacts) working. Fixing data isn't their primary job. And they don't have a moment to waste looking at your contacts to see if there's someone they'd like to call. Put someone in with a totally wrong ZIP code (like someone in Los Angeles with a ZIP code starting with 6 - which is Illinois) and they'll never change it for you. It's wrong, if they see it they'll know - but they'll never be looking at it.

And the VPN keeps a log of every connection you make, so that keeps it nice and centralized, if the government ever wants it. Bad idea.

Don't turn on your voice recorder. The Pixel doesn't record "all the time".

Then turn Photo Sync off. (Although even if you had pictures of a plot to overthrow the government, I doubt that anyone would ever find them.)

They don't, any more than anyone else on the internet does. If you don't run a VNC server, no one does.

Keep location turned off. Of course, if you lose your phone, you won't be able to use Android Device Manager to find it.

Not unless you want to use an app that requires root access that would "help with this". And none of what you're talking about so far involves root access.

You can run Lineage without rooting. If you root, then install Lineage, you'll have to root again, because (as far as I know - I haven't run Lineage yet) Lineage doesn't come rooted. Does it affect the camera? Not if you still run Google's camera app. If you run a 3rd party camera app, probably. (Google does the HDR in the software of the camera app.)

If you want total anonymity, just do 2 things - never use a phone and never get on the internet. (Also never use a credit or debit card, don't have a bank account, pay cash for everything all the time, don't have a real job [wages have to be reported to the government - any government] ...) Basically, live totally off the grid. As soon as you get on the internet (even from a library's computer) you've left a trail. As soon as you've opened a bank account you've left a trail. As soon as you've applied for a credit card you've left a trail. And any of those 3 is a lot less secure than the data you back up to Google.

So you have a choice - live a totally paranoid life as a hermit in a cave, or learn to live in society, take normal precautions and stop thinking that everyone's trying to get your information. Very few people (other than organizations like your government's taxing agency) care. (I've been on the internet, storing data on servers, since servers used to dial each other up once a day - and I've never had any data compromised or had a "visit from the black helicopters". [And, on most sites, I've used my real name and real location, so I'm easy to find, if anyone wants to look for me.] I've been bothered more by people trying to sell me their brand of religion waking me up, and I don't have "No Trespassing" signs on my lawn.)

(Just don't use your phone for anything illegal. But don't use a computer for anything illegal either. If the police come for you they'll take your phone. But they'll take your laptop, desktop and all your papers.)