Pandoc is command line and does not support PDF, for which it needs pdflatex, wkhtml2pdf or other backends. Personally I print PDF via Evince, which - in Solus, AFAIR, comes pre-installed, and I convert to PDF in Abiword; because Ghostwriter, the markdown application I prefer, has some problems calling Pandoc: as I've already pointed out it seems to use deprecated commands... You can of course launch Scribus but this software is mainly for laying out graphic works like leaflets, magazines... I relied on Scribus to make several photo books exported as PDF/X-3 and uploaded to Blurb. It's a pity that the version in the Solus repo was still the 1.4.8 (instead of the much improved 1.5.4).
To split, merge, rotate and extract pages from a PDF you can download PDFSAM.