Embedding fonts exposes you to all the vagaries of font coding. Outlining is always a safe choice, because it moves the font interpretation to your computer, where you have full control and visibility on the end result.
One of the most requested features for Scribus has been automated bleed. The idea is that Scribus would create the bleed area and export it to PDF – you would still have to adjust the layout to take advantage of the bleed area. In other words, bleed as envisioned would add space to your document around the margins, therefore any object needing to come right to the edge after cutting needs to extend beyond the edge of your page size before you add bleed.
As of version 1.3.4, it's possible to set the bleed for the document. Demanding users will be happy that it can be set for each margin individually. Bleed settings are offered in four different dialogs:
Additionally you can already create the bleed for your pages when you create a new document:
Overprinting is an important technique in professional printing to prevent mismatches with overlapping colours in offset printing. As of version 1.3.4, Scribus now can activate overprinting for individual items in the Properties Palette:
These settings can be overridden in the PDF Export Dialog and general overprinting will be enforced:
The Preflight Verifier has seen some useful enhancements. First, it now also checks for a permitted maximum resolution of images. Second, it will check for GIF files, if desired. GIFs don't belong in pre-press, so that's helpful. Third, the tool will ignore non-printable layers. That's useful if a Scribus file consists of layers, which aren't supported by all PDF formats. Letting Scribus ignore those layers will prevent false alarms from the preflight check.