Yes, he illustrated several of his books, including Mr. Bliss and The Hobbit.
J.R.R Tolkien had a brother called Hilary Arther Reuel Tolkien born in 1894.
She didn't illustrate any of her books (as far as I know, at least).
Tolkien left many sketches and drawings. He even doodled using colored pens during his train rides. The original hardcover versions of The Hobbit were published with his pictures and maps in them, and many of them have been used since then.There is a book, Pictures by JRR Tolkien that contain many of them.
Any posting of the books online are in violation of copyright laws and illegal.
quentian Blake did all the work
No, I do not believe he illustrated any books, be they his own or someone other's
Yes, Priscilla Tolkien, the youngest child of J.R.R. Tolkien, has one son named Michael George Tolkien.
J.R.R Tolkien was a Christian, and that influenced his books. He did not set out to make any intentional comparisons on the Bible.
no
Yes, he had a younger brother, Hilary Tolkien (1894-1976).
Tolkien's hobbit characters can only be found in The Hobbit and The Lord of the Rings. Some discussion of them can be found in his History of Middle Earth books, basically they are notes about the writing and creation of Middle Earth.
Tolkien died on 2 September 1973. He was not suffering from any particular health problems.