How should I organize my dialogue workflow from writer>engine

I'm starting to work on a system to feed lines of dialogue to the HUD class which turns them into speech bubbles and displays them correctly, and I'm a bit lost on how I should actually be importing and accessing the dialogue- I'm assuming that writing it in excel and importing that as a CSV makes the most sense, but how the heck do I go about organizing my CSV to make it easy to write, and easy to use?

The best system I've come up with is using a different CSV for each category of dialogue (one for cutscenes, one for generic barks players broadcast as you walk past, one for merchants, etc), but it quickly spiderwebs in complexity. As an example, a story cutscene needs to know the order its lines will be read in, who the speaker of each line is (so the HUD can position the bubble over the correct guy's head), and any logic that needs to occur (like a story-motivated loss of health, or gain of an item). That's already three things that a writer needs to do correctly: assign the correct line number to each line, curate and correctly use some GUID/unique accession system to remember who's talking, and understand enough of a custom scripting language to add things from an inventory database.

Is there a simpler workflow I'm missing? It seems like what I'm proposing would create an unacceptable number of chances for clumsy fingers/inattention to create an extremely hard to catch error.