Yes, there are many opinions given in the forum, but there are many in here that give sound advice that can be backed up by facts as well. In the case of how much weight a floor can handle, the response that I see given by most people is to either have a contractor look at the subflooring to see if it will be ok, or some others say you don't need to worry if the tank is a 55G-75G or smaller, but any larger, they recommend having the subflooring checked. I have never heard of a 75G going through the floor on any floor, but I've heard a few horror stories of 300G tanks. And I usually say that if it's going to be larger than 55G, have the floors looked at if you are not comfortable, or don't know how to check them out yourself.
But overall, I highly doubt anyone can get in trouble by giving advice, because it's the responsibility of the other person to get the facts. And I've been given much advice on here, and it's all been sound advice, backed up by facts. And you can usually weed out the bad advice, as it's usually quite noticable.