Getting a 48-page booklet professionally printed. The printing company states we should export as PDF (x1 a 2001) with fonts converted to outlines, but is that necessary? Also should it be exported in pages or spreads?
Normally you should export this as single pages (not spreads). As for the other export settings, you should use your printing company's requirements.
As a general rule, its not always necessary to convert the fonts to outlines, nor is it necessary to use the 'x1 a 2001' standard. Most printers can handle any kind of high res export, but if they do make specific requirements, you should follow these to make sure they wont have any problems.
I do admit however that converting a 48-page document to outlines is a bit unusual, but they must have their reasons.