HN user
I'd not compare Nix to other three. Yes, you are right, it is kind of "distro-agnostic/sandboxed/multiple-versions", it "need to install to a root directory" and does not "need a runtime daemon", but otherwise it is totally different and much more than others.
TiddlyWiki is quiet flexible. I've rearranged a lot of stuff in my setup.
The "plugin" that you linked is for the older version of TiddlyWiki (it's called TiddlyWiki Classic now).
There is a plugin for the modern TiddlyWiki (IIRC it's full name is TiddlyWiki5) called GSD5 (GSD is for "Getting Stuff Done"): http://gsd5.tiddlyspot.com/ .
I've never used TW Classic and original mGSD, but GSD5 is "heavily inspired by mGSD" and on first glance they look alike a lot.
And, anyway, TiddlyWiki5 with GSD5 rocks.
Wire is indeed awesome. However, as far as I can see, it's still questionable, whether it is as secure as developers tell us and if it really could be "trusted". AFAIK, Signal's developers said something like "we do not recommend to use Wire/Wire's protocol" (however, it all could be kind of political).