There is a legal difference between taking donations before an actual production is done and making a profit selling a copywriten product. The later is a clear cut violation where as donations before production is harder to enforce because the funds could be going towards the production company needs (servers, rent etc.) and that doesn't expressly prove a copyright violation, even though the goal is to make a Star Trek product.
Exactly. Very well said.
Keep in mind, that even if you are not commiting a profit violation by soliciting funds beforehand, CBS Legal still can shut you down on the grounds of you even using 'Star Trek'. This usually does not happen because they don't want to set a precedent that could harm the fanbase. But, they could play that card if they see something that could effect there profits and/or brand integrity. Usually these are on a case by case basis.