I think Farage’s policy will be extremely popular.
Yes it will mean a lot of legal changes. But actually the reality is that changing things legally is not difficult in the UK. We don’t have a written constitution to stop certain changes, or prevent withdrawal from international conventions.
The issue has been that the UK has generally been the promoter of legal certainty and supported international law. But it does not have to.
Point one; withdraw from the ECHR. Now if you are liberal and think everyone has the same rights, then you see a lot of risk in it. If you don’t, then the ECHR is going to stop you deporting people without notice. Or having nationality based policies.
It also means pretty much all of the equalities legislation and initiatives bars on it would have no legal basis at all. This is in part what is meant by free speech or freedom of action. Police racist to you? Tough shit.
Yes this policy is the gateway to dismantling the Human Rights Act, Equality Act etc.