According to Wikipedia, Louis de Branges de Bourcia has obtained some notable results, such as a proof of the Bieberbach conjecture in 1985, which is now known as de Branges' theorem. Initially, his proof of this result was not accepted to be correct. De Branges also claimed to have found a proof of the Riemann hypothesis in 2004. The most recent version of this work dates from 2012.
Which methods does de Branges use in his purported proof of the Riemann hypothesis, and which are his key ideas?
Which precisely are the flaws in de Branges' work, and why is it thought that these flaws cannot be repaired in any straightforward way?
Does de Branges' work also have some significant value independent of whether it constitutes or contributes to a proof of the Riemann hypothesis?
Which materials would one have to read as a non-specialist in order to understand de Branges' work?