I suspect Farage and co are doing what most if not all politicians do when not in power. Promise the earth without any detail.
This is very similar if not the same as what Labour did before the last GE , infact all political parties do it.
Then if and when they get in, they conveniently forget many of their promises and do something different, like put up taxes, squeeze the welfare budget and scrap the winter fuel allowance ?
Nothing changes with politicians im affraid, they are all cut from very similar cloth when it comes to not being honest with the electorate.
There is also the small issue that all new Governments struggle with, it's much easier to be in opposition than to be in power.
You have to take everything they say in opposition with a pinch of salt.