Muhammad was a member of the Quraysh.
By lineage, yes, and a member of the Banu Hashim at that. Tribal affiliations mean nothing compared to one's status as a Muslim, however.
The Quraysh simply wanted to practice their religion in Mecca in peace,
The Quraysh could not tolerate criticism of their false religion and responded to words with violence:
"When the apostle openly displayed Islam as God ordered him his people did not withdraw or turn against him, so far as I have heard, until he spoke disparagingly of their gods. When he did that they took great offense and resolved unanimously to treat him as an enemy, except those whom God had protected by Islam from such evil, but they were a despised minority." - Ibn Ishaq, Sirat Rasul Allah, 166-167
The Quraysh begged Abu Talib to let them kill Muhammad for criticizing their religion:
"They said, 'O Abu Talib, your nephew has cursed our gods, insulted our religion, mocked our way of life, and accused our forefathers of error; either you must stop him or you must let us get at him, for you yourself are in the same position as we are in opposition to him and we will rid you of him.' He gave them a conciliatory reply and a soft answer and they went away." - Ibn Ishaq, 167-168
Islam and Muhammad (SAWS) were persecuted because they were contrary to the pagan barbarism that prevailed in Makkan society at the time.
"The apostle continued on his way, publishing God's religion and calling men thereto. In consequence his relations with the Quraysh deteriorated and men withdrew from him in enmity. They were always talking about him and inciting one another against him. Then they went to Abu Talib a second time and said, 'You have a high and lofty position among us, and we have asked you to put a stop to your nephew's activities but you have not done so. By God, we cannot endure that our fathers should be reviled, our customs mocked and our gods insulted. Until you rid us of him we will fight the pair of you until one side perishes,' or words to that effect. Abu Talib was deeply distressed at the breach with his people and their enmity but he could not desert the apostle and give him up to them." - Ibn Ishaq, 168
"Then the Quraysh incited people against the companions of the apostle that had become Muslims. Every tribe fell upon the Muslims among them, beating them and seducing them from their religion." - 170
"While they were talking thus the apostle appeared, and they leaped upon him as one man and encircled him, saying, 'Are you the one who said so-and-so against our gods and our religion?' The apostle said, 'Yes, I am the one who said that.' And I saw one of them seize his robe. Then Abu Bakr interposed himself, weeping and saying, 'Would you kill a man for saying Allah is my Lord?' Then they left him... Abu Bakr returned that day with the hair of his head torn. He was a hairy man and they had dragged him along by his beard." - 184
"The apostle had gone back to his house when he (Hamza ibn 'Abd al-Muttalib) passed by this woman, who asked him if he had heard of what Abu'l-Hakam ibn Hisham had done just recently to his (Hamza's) nephew, Muhammad; how he had found him sitting quietly there, and insulted him, and cursed him, and treated him badly, and that Muhammad had not answered a word." - 185
"Islam began to spread in Makkah among men and women of the tribes of Quraysh, though Quraysh were imprisoning and seducing as many of the Muslims as they could." - 187
"Then he ('Abdullah ibn Mas'ud) turned towards them as he read so that they noticed him, and they said, 'What on earth is this son of a slave-woman saying?' And when they realized that he was reading some of what Muhammad prayed, they got up and began to hit him in the face; but he continued to read so far as God willed that he should read. Then he went to his companions with the marks of their blows on his face. They said, 'This is just what we feared would happen to you.' He said, 'God's enemies were never more contemptible in my sight than they are now, and if you like I will go and do the same thing before them tomorrow.' They said, 'No, you have done enough, you have made them listen to what they don't want to hear.'" - 202-203
"Then the Quraysh showed their enmity to all those who followed the apostle; every clan which contained Muslims attacked them, imprisoning them, and beating them, allowing them no food or drink, and exposing them to the burning heat of Makkah, so as to seduce them from their religion. Some gave way under pressure of persecution, and others resisted them, being protected by God. Bilal, who was afterwards freed by Abu Bakr but at that time belonged to one of B. Jumah being slave-born, was a faithful Muslim, pure of heart. His father's name was Ribah and his mother was Hamama. Umayya ibn Khalaf ibn Wahb ibn Hudhafa ibn Jumah used to bring him out at the hottest part of the day and throw him on his back in the open valley and have a great rock put on his chest; then he would say to him, 'You will stay here until you die or deny Muhammad and worship al-Lat and al-Uzza.' He used to say while he was enduring this, 'One, one!' (expressing belief in one God.)" - 205
"The B. Makhzum used to take out 'Ammar ibn Yasir with his father and mother, who were Muslims, in the heat of the day and expose them to the heat of Makkah, and the Apostle passed by them and said, so I have hear, "Patience, O family of Yasir! Your meeting-place will be Paradise.' They killed his mother, for she refused to abandon Islam. It was that evil man Abu Jahl who stirred up the Makkans against them. When he heard that a man had become a Muslim, if he was a man of social importance and had relations to defend him, he reprimanded him and poured scorn on him, saying, 'You have forsaken the religion of your father who was better than you. We will declare you a blockhead and brand you as a fool, and destroy your reputation.' If he was a merchant he said, 'We will boycott your goods and reduce you to beggary.' If he was a person of no social importance, he beat him and incited people against him... I said to 'Abdullah ibn 'Abbas, 'Were the polytheists treating them so badly that apostasy was excusable?' 'Yes, by God, they were,' he said, 'they used to beat one of them, depriving him of food and drink so that he could hardly sit upright because of the violence they had used on him, so that in the end he would do whatever they said.'" - 206-207
Shall I continue?
The hijra to Madinah followed a smaller hijra of a few Muslims to Abyssinia; the Quraysh followed the Muslim emigrants all the way there simply so that they could bring them back by force and oppress them once more. The hijra to Makkah was undertaken by a far larger number of Muslims, including Muhammad (SAWS), in order to escape polytheist oppression once and for all. His reputation as a fair-minded settler of disputes earned him an invitation to the city by the Madinan community. The raids on Makkan caravans were not approved of by Muhammad (SAWS) until it was discovered that the Quraysh had been stealing and selling the property that Muslims had been forced to leave behind in Makkah. Tensions escalated and the Makkan army was eventually routed by a smaller and more ill-equipped force of believers, who went on to take Makkah.
and it was Muhammad who murdered female intellectuals and poets who criticized his repressive and violent belief system
Nobody was killed who did not incite violence against Muhammad (SAWS) or the community of believers. That is the recompense for those who threaten the existence of Islam.
and it was Muhammad who stole the land of Jews and Christians simply because they wished to practice their own religion.
War was not initiated with any group that did not declare hostility towards Islam or support others against it. If you can cite specific examples of this taking place, I'll be happy to clarify.
