Hi Tony.
You are right, this definitely requires the user to learn about vue.js.
This is limited to be used inside a tiddler. The tiddler content is the vue.js template. Of course, you cannot have javascript or CSS in a single vuejs tiddler.
The default vuewrapper initializes a vue app with the tiddler fields in the "self" namespace. It binds the fields so all changes are synced, between TW and the vue app. It also allows you to import other tiddlers data. I want to add support for lists with TW filters and data tiddlers with indexes and json.
That limitations are the reason to include the library of components UIV which uses Bootstrap. This way you have some functionalities without writing javascript and css, such as modals, tooltips, buttons, radio buttons, date picker, dropdowns, and others. Ceck out the UIV documentation
https://uiv.wxsm.space/getting-started . I am thinking on changing uiv for another libray (suggestions are welcome). By having a library of components you can avoid writing javascript logic.
You could add javascript behaviour by adding a vue component as a javascript library. I am putting this in the roadmap. So you will be able to write a vue component with special functionalities that are not possible to do without custom javascript. However this would be way more advanced.
For now I think the main applications for this is having javascript expressions inside tiddlers. I remember I posted a while ago a widget that allowed you to update a field with a math expression and required math.js plugin. I think things like adding or multiplying two fields should not be that hard. In vue.js it is quite simple {{ self.fieldA * self.fieldB + self.fieldC }}. Or, say, hiding a div when some condition is met:
<div v-if="self.fieldX > 10 ">
But right now the TW WikiText syntax for this is more complicated than it needs to be or is just not possible (yet).
Right now you can't transclude. It could be possible, as TW makes this easy, but it needs more thought and work. Perhaps I'll add support for that in the future or someone else that needs that functionality sends a pull request.
The application for this that I have in my mind is more like a behavior similar to excel, where you can easily put formulas and manipulate the data in the spreadsheet.
This definitely needs more examples. If you come up with nice example ideas, I can write and add them to the documentation so people have a better idea of what can be done.