I may not have addressed all your questions but here are some:
Pale Moon - In terminal (ctrl+alt+t) execute these one by one:
echo 'deb /repositories/home:/stevenpusser/xUbuntu_18.04 - openSUSE Download /' | sudo tee /etc/apt/sources.list.d/home:stevenpusser.list
curl -fsSL https://download.opensuse.org/repositories/home:stevenpusser/xUbuntu_18.04/Release.key | gpg --dearmor | sudo tee /etc/apt/trusted.gpg.d/home:stevenpusser.gpg > /dev/null
sudo apt update
sudo apt install palemoon
[CITING THE SOURCE FOR ABOVE COMMANDS, DO NOT RUN THIS IN TERMINAL] - Install package home:stevenpusser / palemoon
Backup - please see the following:
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