Not really possible if a paywalled website is a true paywall. Many paywalled websites don't even expose their content to crawlers.

I also think that, philosophically, the majority of the user base being able to bypass paywall isn't healthy for the Internet. It will only make content quality decrease and advertisement aggression increase. You can see this effect come into play with pages that use anti-adblocking tools, where you can't see anything until you disable ad blocking.

> Tab freeze for tabs not in focus - save CPU and battery energy

Chrome energy saver mode? Safari seems to effectively do this, tabs seem to be pretty dead until you are using them. I would also ask what kind of need there is to save battery life above and beyond present technology. Modern laptops sold on the market now can be in a web browser for an entire workday (e.g., ASUS Zenbook 13 OLED, any MacBook M1/M2).

Almost everything on this list is already available with browser extensions or existing browsers.