The downgraded versions don't necessarily just take some modules away, they rather limit functionality, features or quality. That's not very comforting for a professional workflow, because the features cut from the full premium versions are in most cases critical ones.
I don't know how tough the demands are for what Eric is going to do with video, but the complexity of the average gonzo porn videos don't seem that high-end to me. Some Vivid title, basically a gonzo flick marketed as a feature, mentions the use of Final Cut Pro for video and Pro Tools, a professional audio studio standard, for audio in the credits.
Vivid won't have to mind about the cost of their workstations, but someone else, maybe like Eric, will want to do things more cost-effectively.
Professional versions of a video editing suite might be a good idea, although they can be overkill for the gonzo market in some cases. Audio editing can be done in audio sequencers like Cakewalk Sonar, Apple Logic, Steinberg Cubase or others, which cost a fraction of Pro Tools when bought. And, to be closer to how software is actually used, it'd be fair to mention once more that there's always the possibility to just use the most current versions of tools, not in every case the most current one legally available, cracked and basically for the cost of the hardware to run it plus some broadband internet access.
It'd depend on how accepting the people in the industry are, should there be any traces of meta data or whatever else might be put in the output files that states the cracked nature of the source program. Going legit all the way is fine, but can cost a lot of money. People who are just starting to learn the use of complex tools might want to test all the major ones out and stick to the preferred one.