it would take a book to answer that question and even then no one else would agree A lurcher is a lot of different things to alot of different people, depends on quarry, terrain, culture, current fashion and a shit load of other factors. The one thing that everyone seems to agree on is that they are right and have "proper" dogs and everyone else is wrong and have "messer" dogs
As long as yours does what you need it to do for you then i would say its a "proper" lurcher