"Am I correct in thinking that our Membership of the Council of Europe, subscription to the European Convention on Human Rights and coverage by the European Court of Human Rights are unaffected by the result of the referendum, as this is a separate thing to the European Union?"
This is correct.
The Council of Europe is not an EU body. The EU has 28 member countries, whereas the Council of Europe has 47 member countries.
The Council of Europe is principally concerned with human rights. Its 47 members are all party to the European Convention on Human Rights and are subject to have laws challenged in the European Court of Human Rights in Strasbourg if they are seen to be in breach of the convention.
It therefore follows that a country can be a member of the Council of Europe without being a member of the EU, and Britain’s membership will continue regardless of the referendum. It is not the current government’s policy to change this or pull out of the European Convention on Human Rights.