Nigel Farage wants to be taken seriously as the leader of a potential party of government, so let us take him at his word: his ideas for government are terrible.
He should be taken seriously because he has a good chance of being prime minister after the next election. It is no use saying, “The election is probably four years away; anything can happen.” The things that might happen are just as likely to increase Farage’s chances of winning as they are to decrease them.