While some people have had problems creating mixed mode CD-ROMs, other companies have had good success. It depends on how much time they are willing to spend on development and testing. The most common reasons for problems is that the media files are in the wrong formats or don't conform to the eight character restriction of DOS. A good example of a mixed-mode disc is the "Forever Growing Garden" developed by a company called Arborescence located in San Francisco. The CD is distributed by Media Vision.
Regarding the fonts question:
As with most font handling for all applications, if you don't have the corresponding font on the PC, a default font will be used instead. You can use the PC version of StyleEdit (STYLEDIT.EXE) to look at your text on the PC and find a close match if you don't have the corresponding font. Another alternative would be to create a picture, and font substitution won't be an issue.