As I don't know how slapdash you've been the easiest way might be to set up some line weights that you know will work and then select different elements types and collectively change there settings. eg. Select all of the walls, go to their settings and just change the line settings. Make sure you do not change any other settings like wall width or height or you will get changes you don't want. Then select all of the windows and do the same thing etc., etc.
I am not sure why your text is not printing as text doesn't respond to line weight. It could be a font problem or it may be responding to colour if you are printing in greyscale output. In this case just select all of your text and change it to black. I don't know if this is clear but if you could post a sample of a drawing it might be easier to answer particulars.
Hope this helps.
Gerald Hoffman
“The simplification of anything is always sensational” GKC
Archicad 4.55 - 27-6000 USA
2019 MacBook Pro-macOS 15.0 (64GB w/ AMD Radeon Pro 5600M GPU)