(1) So how then does the requirement for a Shaykh fit in to all of this? There is no need for a Shaykh in this day and age IMHO. Hence, there is no requirement for a Shaykh. (2) What are the evidences that suggest that a Shaykh is required? There are no evidences in Islam to suggest that taking a Shaykh is required. Even though, Tasawwuf people over exaggerate the importance of taking a Shaykh but it is not a religious requirement. (3) Ultimately it is down to the individual, is it not? Yes. With the internet nowadays, it is so easy for find amazing speeches and teachings of Islam of so many authentic religious scholars from around the world. Why limit yourself to one Shaykh especially when the Shaykh tells you that you can't listen to lectures of any other Shaykh. (4) Related to question 3, what difference will a Shaykh make? Many people have benefited from taking a Sufi Shaykh. But then, a lot of people do things to please the Shaykh and they do it because the Shaykh told them to do it and many times, Allah is completely taken out of the picture. There is a huge potential for Shirk in taking a Shaykh. Considering all the harm nowadays because of Sufi cults and the cultish behavior of Tasawwuf people, it's best not get involved with any specific Shaykh. If you do, there is a very strong possibility that you will start hating other Muslims as can been seen by the behavior of the followers of some Shaykhs. There is A LOT of rivalry and hatred between the followers of various Sufi Shaykhs. Find scholars who you like and listen to their speeches and you will benefit tremendously from them. Nowadays, many people don't have much contact with their Shaykh anyway. Also, if you are not sure about anything or are weak in some aspect of Islam, you can always listen to a lecture on that topic or even email the many online Fatwa websites. They will answer whatever question you have even about Tasawwuf.