I'll admit that I'm very interested in Soylent, and I'd like to try it myself. But I completely agree with you on this.
Soylent is the sort of thing that could seriously damage your health. I know that several people have trialled it over the course of a few months, but nutritional deficiencies can take much longer to develop. For example I don't recall ever reading that oral health was being monitored during the trials - when you're not chewing anything, your teeth will fall out.
I'm sorry but I truly do believe that selling Soylent would be dangerous and irresponsible. Please, don't sell Soylent to anybody until you've done some proper clinical trials.