Basically, "Make Layer Visible" checkbox is there only to temporarily show or hide content of a layer
in Scribus. Note that this checkbox doesn't affect printing and/or exporting to PDF in any way, i.e., even if you hide a layer, but "Print Layer" checkbox for that layer isn't ticked off, you'll get full content of the hidden layer printed and/or exported to PDF. So, if you want to hide something
in the output, on paper and/or in PDF document, then you'll have to tick off "Print Layer" checkbox.
Note on colors: If "Output intended for: Printer" is activated in PDF export dialog, tab "Colors", then all colors will be automatically converted to CMYK. If "Output intended for: Screen / Web" is activated, then conversion will not occur.
Note on fonts: Scribus handles fonts very nicely, be those TTF or OTF. Here's just a tip regarding OTF fonts: if you want to embed an OTF font instead of subsetting it, then in
File > Preferences > Fonts tick off "Subset" for that font. Don't forget to always check PDF export dialog for fonts to make sure they are correctly embedded, otherwise prepare for unpleasant surprises
Note on printing: Never print directly from Scribus. Always export your document to PDF and print from Adobe Reader (or any other PDF reader).
Note on graphics: Make sure that resolution of included images is at least 300dpi, if you're planning to print the document. Also note that Scribus does not (normally) embed images, but rather create links to them, so, if you move or rename images (or folders containing them), the links will be broken and you'll end up with empty image frames in Scribus.
Note on files transfer: When transferring your project to another computer, use "File > Collect for output". This way you can be sure that all necessary files are collected and transferred safely. Sending plain .sla file isn't enough.
Best of luck
