Based on all the above, I suggest KWord or KWrite. Both are from (or involve) KDE, so they depend on the base-library packages of KDE, which are kinda large, but if you want a REALLY good text editor that can do everything you want, KWrite is my suggestion. I've tried other editors, and am still experimenting too, but I *still* have KWrite because the smaller editors just aren't as friendly and easy to use for anything more than a simple text file.
What I propose if you want to trim down the installation size,
(and this is what I am going to do for my own system, because I really like KWrite) is this:
--install the dependencies/libraries and whatnot for KWrite (so this means install KDE basically, at least the base-libraries, maybe base-runtime, and utilities (or whatever chunk of KDE contains KWrite)). Choose a stable version of KDE for this. Maybe 3.5.x would be nice and reliable.
--now, identify which libraries KWrite depends on to work.
--copy the kwrite binary, and its dependencies, and make them into a standalone package for your OS.
--install your new little kwrite standalone package.
So, not sure if this plan fits into your own "willing to try" category
but it's a thought.
Best of success, whatever route you go. And do let us know what editor you decide on in the end.