NoScript will improve your privacy by a lot, and will make webpages load faster, since it stops stylish and tracker-ridden JS. If a webpage breaks, you can flick a few buttons to temporarily allow JS (or permanently if you’ll be visiting that site a lot).
Tor over VPN is a fine solution if you want to hide it from your ISP, but I don’t think you should install extra stuff on TailsOS. Consider using Tor Browser + UblockOrigin on your own PC over a VPN, it’s pretty much the same thing if you’ll just be browsing online.
Oh-- and one important thing to remember: Don’t expend more effort than necessary for your own threat model. Consider the extent of your privacy needs and act accordingly, going overboard will only leave you tired for not much in return.
P.S.: mander.xyz has a Tor-based onion frontpage ;)
Tails with persistent storage is absolutely a good solution for this specific usecase. It’s designed for it and provides a free and secure encrypted proxy solution (Tor). On top of that, your internet activity will likely help the activists who really need Tor by “mixing” your traffic with theirs.
Tails has thunderbird installed by default, you can connect it to your email account (but do take note that proton only seems to allow 3rd party client integration if you install their bridge app thingy)
If it is your own computer, in your home network, just install the necessary apps on any old distro. Doesn’t matter
Personally, I’d say nice to have, but it’s not the end of the world if you decide to use something else