just the hashes on chain would mean a central org can censor anytime .. they wont be any diff than twitter.. the biggest problem with bitclout like on chain socials would be that people wont be able to change for the good or obv go back on what they said.
unless the artwork is copyrighted, it would be very difficult to argue. Also if the seller copyrights it first then there is no chance of claiming any ownership.
This is such a cliche answer! Ofcourse we know who the target customers are, funding would help in hiring and building more features. Thus increasing the value for the customer and the probability of success.