This is where you find yourself reading another 1000 page specification... but fortunately it is not so very difficult to parse a font file. Acrobat has no APIs for this.
OpenType as a standard includes CFF and TrueType, but not type 1. Start here (for OpenType): Microsoft Typography - Features of TrueType and OpenType
Note that a font MIGHT include a cmap to convert between glyph numbers and Unicode, but it might not. A PDF creator is encouraged to strip unnecessary tables from the font files it embeds, and "cmap" is not needed for PDF display. So be prepared for this.
