In ancient times, many kings and princes imagined that when they died they would become like gods and sit among the stars. This belief is even mentioned in Isaiah chapter 14, where his successor, Nabonidus, is derided for having thought that he would sit among the stars, comparing himself to the morning star (Lucifer, from Latin), but was now himself persecuted.
If you mean by Muhammad the prophet, then he considers himself; and Muslim people consider him; the last God prophet and messenger to whom God revealed the Quran and that He is human assigned by God to lead people the right God path and to worship God with no partner, no son, no companion, no associate, and no equivalence. Refer to question below.
King Nebuchadnezzar II (634-562 BCE)
No, he was an idolater. At most, he would have believed that the God of Israel was one among many.
No, Nebuchadnezzar did not write any part of the book of Daniel. In fact, scholars now know that the book was really written in the second century BCE, long after the events it depicts. The Book of Daniel draws a close parallel between the legendary patriarch Joseph, who interpreted dreams for his captor, the king of Egypt, and Daniel, who interpreted dreams for his captor, the king of Babylon. Chapter 4 begins by declaring its author to be Nebuchadnezzar, who describes his dream and how only Daniel could interpret it. Nebuchadnezzar then explains what Daniel told him, but when Daniel's story finishes, verses 28 to 33 accidentally slip into talking of Nebuchadnezzar in the third person - a certain give-away that Nebuchadnezzar had not really been writing. Then verses 34 to 37 revert to the style of having been written by Nebuchadnezzar. Further confusing the evidence for authorship by Nebuchadnezzar, verses 2 and 3 begin by Nebuchadnezzar praising Daniel's God, but verse 8 makes it clear that Nebuchadnezzar has another god and talks of the "holy gods", just as a pagan would. Overall the chapter 'proves' that Daniel's God is supreme, for which reason, Nebuchadnezzar blessed the most High (4:34) and praised the King of heaven (4:37). How could this be if he then sat down and wrote an historical account, unapologetically saying that he had another god? By putting Nebuchadnezzar's experiences in the first person, the author of Daniel was making an otherwise implausible episode seem plausible. His dogmatic statements about God avoided contradiction because they came from no less a source than Nebuchadnezzar.
His disobedience towards God! He had his people serving other gods.
God caused Nebuchadnezzar to lose his ability to rule "for seven periods of time" (Daniel ch.4), which the Malbim commentary understands as being seven years.
Nebuchadnezzar's hair and nails grew long.
Nebuchadnezzar
A better question: is "Why consider the bible to God?" an English sentence?
It's God Himself
No, Nebuchadnezzar is not single.
Well, he does believe in Jesus Christ and God, but he doesn't consider himself as a follower in any religion. He doesn't believe in organized religion.