Please show an example of what you want and what you currently get.
Why are you tracing the text you generate in LightBurn? The text is already a vector shape, although still in a LightBurn Primitive form at that point (right-click to convert to paths). Tracing, to produce vectors would be redundant if I understand your workflow.
Correct. The default is wireframe as we suggest this for laser work to not cover things you might need to see. Have a look at this for more on the subject.
We don’t recommend using filled rendering for editing because LightBurn doesn’t work like a traditional paint program - things “behind” a filled shape may still be sent to the laser, so Preview and working in ‘wireframe’ / outline mode is safer.