When questions are posted promoting products or commercial web sites they are removed.
Many of the questions are asking for an opinion so there's no way to evaluate it for truth. There are others that the person asking it doesn't provide enough information for an exact answer. For example a question that asks about the law can't accurately be answered if you don't know what country they are in. Putting up your opinions is OK but I wouldn't put up an answer knowing it's factually untrue though.
As far as 100% accuracy is concerned, you don't know. That's the value in having a number of people answer the same question. The person asking gets different viewpoints and when the answer is wrong, usually someone else will point out the flaw in it.
This site also has reputation scores. When someone posts a good question or answer, readers can click on the up-down arrows and add or subtract from the writer's reputation score. If you want to know someone's rep score, click on their logo.
