I’ve lost track of how many lawsuits I’ve seen between co-owners of New York City restaurants. It’s not surprising given the high percentage of restaurant failures in an intensely competitive market with high rents, high labor costs, and high everything else. Another significant factor is the heavy initial investment required for start-up restaurants in the city. Aspiring restaurant entrepreneurs long on ideas and talent but short on cash and credit often will bring in friends and family as silent partners to provide the capital…