Question 3:
Can I ask why God stopped sending books and prophets? Like did he get tired?
Answer 3:
No. God can never get tired.
God wrote in the Quran that Prophet Muhammad is the seal of the prophets. The best thing for you to do to answer your question would be to read ALL God's books.
If you study the Quran you should come to the conclusion that there is no need for a new messenger. Every information has been detailed in the Quran (This was also true for the Torah).
Another reason is because unlike the other prophets of God who were sent to their people. Prophet Muhammad was sent to ALL mankind as a whole.
Another reason is that the Quran cannot be corrupted like God's other books which He sent down, which have been corrupted; Some things have been removed from them and some things added. God said in the Quran that He will protect the Quran. Since there is no problem with the Quran, there could be no need for a new book or prophet.
The quick way for you to answer your question is to read the part of the Quran where God talks about the creation of man (Q2:30-39).
When Adam was being sent out of the Garden, God told him that He will send guidance; that whoever follows the guidance there will be no fear on them and they will not grieve. And those who disbelieve and call the signs lies will be companions of the fire and they will dwell in it forever.
That was a promise that God made to us. And God will definitely keep his promise. If there are no more messengers it could mean that we are running out of time. The world must end one day and Judgment Day must come.
Also, there is a part of the Quran (Q77:50, Q7:185, see also Q45:6) where God said,
"In what story after it will they believe?"
This means if someone does not believe in the Quran there is nothing after it that they will believe in...
I think the most important reason is that God does what He desires. If He says there will be no more prophets, who are we to question that?