> If I have my PC mining and then disconnect it, does the Bitcoin network suffer in any noticeable way? Yes, there's a computational power threshold to perform

> If I have my PC mining and then disconnect it, does the Bitcoin network suffer in any noticeable way? Yes, there's a computational power threshold to perform certain attacks against the network, and removing your node marginally decreases that threshold. Is it necessary? That depends on your priorities and your threat model.