I think you're overreacting Holocron, it's not really as bad as you think. Let me answer some of the issues you brought up.
A- Compatibly. Yes there will be problems with that, and unfortunately there's no avoiding it. It won't exactly **** up the game, but it will just be weird seeing the PC voiced in some conversations and not in others. However, I'm perfectly happy playing vanilla k1 with a voice mod like this.
B. - Dedication: You'd be surprised on how many people would be willing to do such a project. Look at game developers, they put 3-4 years of their life into developing a great game. Take Mass effect, for example, the amount of effort into making such a game the way it is is much more than doing a project like this, so really dedication will probably be an issue at times but it's not like you need to be insane to do the project.
If you're suggesting that everyone does have a short attention-span (I know some people do, but then again when you have experience it lengthens it), then we wouldn't see all of the mods out today, I.E. - TSLRCM