90% of the users do not read before writing. If you do, you will get many merits and will be considered a good poster.
I recommend that you just ignore any thread with more than 15 replies. Some very specific threads are an exception to this rule imo. After 15 replies, most of the time, everything was already said and spammers join in
I'm not sure on that point. If I have a doubt on any topic, I usually do a general search and look for answers. The post that I find might have 20 responses and there's a probability that I'd want to contribute to the discussion - just so that I understand it better.