Yvori
Terrarian
I'd have to agree with all your input, for the most part.
You did of course, miss a few Etherial items. I'll state my opinion on them from my testing.
Etherial Frost: Utterly useless, unfortunately. Applying Frostburn is something countless items from countless mods, and even vanilla, already do. Certainly not worth a slot.
The World of Etheria: Much like the other timestop items, sounds like fun but isn't all that useful. (See below for further explanation)
Etherial Truffle: If I recall, it's a nice boost. But again, sometimes situational unless you build an arena to make the most of it.
Issues with timestop (contd.): The primary issue plaguing timestop, an otherwise very cool expert-only mechanic, is that you essentially need to build around it entirely for it to be useful. When you first get it, it's utterly useless.
-Sands of Time; well, you need to use an accessory slot for Sands of Time to even be able to do anything while in timestop. Even then, it lasts only a few moments before entering a 30 second cooldown, you barely have time to switch to another weapon before it runs out.
-Time Winder isn't all that important, given that at the point you gain access to it, you'll already have good, even great movement abilities, and being able to dodge around better while enemies are frozen isn't all that important.
-Clockface is great, reducing cooldown time, although I forget by how much- I do recall it wasn't enough to make building for timestop worthwhile.
-Hands of Time is again, necessary for using timestop, since it increases that timestop to an almost-bearable length (barely.)
-Father Time, combining the above three, is great, except that it still requires the use of the Sands of Time on top of it to have any value, so still two whole accessory slots out of a maximum of 7 (assuming you're just using Enigma and not a bunch of other mods which happen to add more), where usually defensive or offensive boost accessories will usually be far more useful than a brief timestop with a long cooldown.
-The World of Etheria does essentially nothing, just making it so your projectiles hit the boss before timestop ends rather than after, which doesn't really matter unless you're using some super piercing weapon that breaks horribly when the same type of projectile hits at once (in which case you'd be better off using a Piercing Projectile Fix). It certianly isn't worth an extra accessory slot (or two extra accessory slots if you intend to use it outside of the Etherial, because of the Globe).
While it functions... very suspiciously similarly, I'd reccommend looking to the Antiaris' implementation of timestop in their Time Paradox Crystal item. It doesn't require any accessories to use effectively, simply having a decent-length timestop (10 seconds by default if I recall?) although an unpleasantly long cooldown. Despite both items being somewhat buggy especially when used with certain weapons that don't work well with stopped projectiles (example: staff of explosion from WeaponOut, unfortunately, since it's one of the things that would benefit from the freeze best) they have lots of potential for being very fun, but are both just implemented in a way that makes them more tedious than exciting.
, way too many things at once, impossible to understand anything, his projectiles deals waaaay too much damage and literally *blends in with the background*. 
