I want to make changes to existing dialogue and etc. but these: * appear next to the entries and the topics and is that something bad?

Maybe I'm making everything out to be extra difficult and I can just change things and save them and not have to clean the mod and/or add new topics as a copy of the original to edit them safely

(which seems to be suggested here??? http://abitoftaste.altervista.org/morrowind/index.php?option=content&Itemid=10&task=viewpost&id=58&-Morrowind-modding-for-smarties-part-5-dialog-editing-fixing )

or WHATEVER is necessary but I'd just like to know for sure beforehand.

I've found people saying you shouldn't delete existing topics at any cost which makes sense but also stuff like: 'Avoid using built-in topics. This could cause significant interference between mods that modify the same topics.'

does that just mean I shouldn't add a new topic with the same name?

or should I not modify exisiting topics??

Because that is what I want to do

please help my noob self

(and how do I change dialogue etc. safely if not simply retyping them?)