Is answering a religious question, while knowing the answer, considered an audacious act of issuing a fatwa, and is issuing fatwas restricted to people of knowledge only?

The default is that issuing fatwas (religious edicts) is for scholars only. However, there is no harm if an ordinary person is asked about a ruling they know by consensus—such as the prohibition of alcohol or zina (unlawful sexual intercourse), or the obligation or recommendation of something—and they respond accordingly. This is not considered audacity in issuing a fatwa, and they will be rewarded for it. But if they issue a fatwa without knowledge, then they are audacious.