Font usage (=fonts embedded in Illustrator)for stock design (=commercial purpose)

I will assume that by “fonts incorporated in Illustrator” you actually mean fonts that are installed by Adobe as part of the installation of Illustrator. My response also applies for any other fonts licensed from the Adobe Type Library directly from Adobe.

You may use and embed fonts using Illustrator, InDesign, and Photoshop PDF and EPS output file formats without any restriction. That includes embedding them in files that you license to others. You don't need to outline or rasterize the text to remain legal. In fact, outlining degrades output quality since you lose “intelligent scaling” provided by the font technology and font definitions with result of overly bold and blotchy looking text at low magnifications and resolutions. Rasterizing is even worse since the results are tied to a particular resolution.

What you may not do is to sell artwork in .AI (Illustrator), .INDD (InDesign), or any one of the Photoshop formats with layers preserving live text and include the fonts as separate files. (You obviously could distribute such source files without the fonts and point your customers to where to license them!)

Clearly, the best option in terms of output of your artwork and designs for resale would not outlining or rasterizing text and saving or exporting as PDF (either PDF/X-4 or High Quality Print options) maintaining color management and live transparency (if used).

          - Dov

PS:  This advice with regards to fonts may or may not apply to fonts sourced elsewhere. You must read the EULA (End User License Agreement) associated with the fonts you plan to license. Some may allow embedding but require royalties for the distributed PDF or EPS files that have the fonts embedded. Some prohibit outlining or treat outlining the same in terms of restrictions as embedding the font itself. And some have similar restrictions on rasterization. Check such terms before you license a font!!! Yes, you must read the licenses!