I can sympathize with your concerns, but the old saying goes, "If it works, don't fix it". We don't have any red flags, but we do have other ways of getting attention. First, there is the chatterbox, which could get you an answer in minutes if you're lucky. In the case where you post a question to SoPW and don't get a satisfactory question, you can update your original post calling attention to it; or you could take a good hard look at your question to see whether you have asked it in a useful way. The problem may not be lazy monks, but rather a poorly-asked question.
It seems to me that Newest Nodes already does most of the things your red flag does. By using it you can see how many replies have been made to a post, and decide whether you want to take a close look. It doesn't help with old nodes, but those should probably be reworked and reposted.