You can take care of #1 the way people here suggested, but I believe you can also do it backwards by having firefox delete ALL cookies at exit and whitelisting

You can take care of #1 the way people here suggested, but I believe you can also do it backwards by having firefox delete ALL cookies at exit and whitelisting some domain's cookies. (Cookies sand Site data, check "Delete cookies and site data when Firefox is closed" and hit Manage Exceptions right next to it to whitelist some domains) For #2 you do not need Firefox's VPN service. I am using it with wireguard and a socks5 proxy on the other end. I have a 'proxy' container configured but you can have more than one container with proxy as well. (In advanced proxy settings the syntax is socks://10.0.99.82:1080 )