It would be easy. Just install Waydroid and install an android app on the Android system. Look at Waydroid official install guide and maybe watch a video.
Lemongrab
It shouldn't be too taxing on the Pi 4 or 5, Waydroid runs an LXC container with x86_64 LineageOS. It works well, but requires Wayland.
It does not use adblock plus lists directly. The lists are hosted by Cromite. uBlock Origin is not available for any android chromium browser (other than kiwi I guess). The adblocker works well from my tests. I recommend adding filterlists from https://divested.dev/pages/dnsbl
It is not security hardened from what I can tell. Most of Librewolf's patches could be applied to build Zen with security hardening. Alternatively, patch Zen browser with Arkenfox user.js (upstream project to Librewolf's security hardened default profile)
Universal Blue and Wayblue offer most of the desktop environments available for Linux.
Use Cromite. Fully open source, adblocking, and security hardened. See this browser table for conparisons: https://divestos.org/pages/browsers
Yes, most DEs use X11. I dont think that is a good thing. XFCE will take a bit to implement Wayland (approx 2 years according to their update schedule).
Better for newbies because it is harder to break.
Body hair makes it harder to chafe and more comfortable when in a hot sticky climate since the skin sticks less to eachother. Also, having curly body hair increases the chance of in-grown hairs and that feels awful.
Privacy.com allows you to create virtual cards, allowing you to set up rules for how money can be used through them. It also masks the receipt details that your bank would normal get access to so they can't sell that data about what you purchased.
Magic Earth isnt FOSS though, which was specifically requested by OP