Assalaamu alaykum. There is a girl in my locality who says that there is no problem with taking selfies if you are wearing a hijab (covering the hair only). She rejects face covering and calls it an 'Arab tradition'. A friend of her once said that she wants to marry a boy who has a beard and is religious committed, so the girl insulted her in front of the whole class and said, "He'll beat you up," and, "Extremists do not understand Islam." She also says, "Qadianis and Shiites have their own rights, you have no right to intervene in their actions."
So, Shaykh, what is the ruling on such people?

All perfect praise be to Allah, The Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad is His slave and Messenger.

Your question included several issues:

The first issue:

A woman taking selfies while she is not properly covered; if the purpose is to publish this picture where non-Mahram (marriageable) men may see it, then it is not permissible for her to do so. Also, in general, there is a difference of opinion among the contemporary scholars about photographic pictures, and those who permitted it are very strict regarding women's pictures in particular, because seeing those pictures may lead to temptation. Please refer to fatwas 83249 and 285556. So one should beware of resorting to it without a need or necessity.

The second issue: the ruling on the niqaab and the fact that this woman claims that it is only an Arabic tradition; this claim is totally unfounded. The scholars did not differ about whether the niqaab is enjoined in Islam; rather, they differed on whether it is obligatory or only recommended. For more benefit, please refer to fatwas ’s wives">115107 and 326989.

The third issue: saying that the Muslim men who are religious and keep a beard are extremists who do not understand Islam and that when they get married, they beat up their wives; this is obviously incorrect. It is injustice to generalize this claim to all religious people, as most of them are pious and moderate in their understanding of Islam, and they give due respect and dignity to the woman. If it is not assumed that those who have a religious appearance and reputation are of good conduct and deal with people fairly, then how can it be assumed that the dissolute people who openly commit sins and are disobedient to Allah and do not abide by His Command are better in dealing with people and more respectful of their rights and keener on being acquitted from sin than those who are religious and obedient? That is very unlikely.

Indeed, a woman is Islamically encouraged to accept a man who proposes to her and is religious and has good moral conduct. Abu Hurayrah, may Allah be pleased with him, narrated that the Prophet said, “If a man whose religion and moral conduct are pleasing to you proposes to you, then let him marry; otherwise there will be great mischief and corruption on earth.” [At-Tirmithi and Ibn Maajah]

For more benefit, please refer to fatwas 25544 and 84474.

The fourth issue: her statement that these sects have rights and that we have no right to interfere in their affairs. This is a general statement that could lead to mixing the truth with falsehood. There must be some details. As for the fact that these people have rights which they must be given and should not treated unjustly, then there is no problem about that. Indeed, the Sharia advised us to be kind to people, even if they are disbelievers, as long as they are peaceful. Allah says (what means): {Allah does not forbid you from those who do not fight you because of religion and do not expel you from your homes - from being righteous toward them and acting justly toward them. Indeed, Allah loves those who act justly.} [Quran 60:8]

However, if by not interfering in their affairs, it means not to expose their falsehood or not to deny their corrupt beliefs, then this is rejected and false. This is because it is incumbent in the religion to enjoin good and forbid evil, as this is a reason for the protection of society from destruction. It was reported that Abu Bakr, may Allah be pleased with him, said, “O people, you recite this verse: {O you who have believed, upon you is [responsibility for] yourselves. Those who have gone astray will not harm you when you have been guided.} [Quran 5:105], and I have heard the Prophet say, 'When people see an oppressor but do not prevent him from (doing evil), it is imminent that Allah will punish them all.'”

As-Sa’di said in his Tafseer (exegesis):

“Meaning, strive to rectify your own selves and perfect it, and oblige it to tread the path of righteousness, and if you become righteous, then those who have gone astray and were not guided to the correct religion will not harm you; rather, they harm their own selves. This does not mean that neglecting to enjoin good and forbid evil does not harm a person, as his guidance is not complete unless he does what is required of him of enjoining good and forbidding evil. Yes, if he is unable to deny the evil with his hand and his tongue and denies it only in his heart, then the misguidance of others does not harm him.” 

For more benefit, please refer to fatwas 5419, 6283and 81427.

Finally, this girl should be advised and warned against this attitude and incorrect opinions that may lead her to disbelief. Tameem Ad-Daari, may Allah be pleased with him, narrated that the Prophet said, “The religion is advice.” They said, “For whom?" He replied, “For Allah, His Book, His Messenger, and for the leaders of the Muslims and their masses.” [Muslim]

Allah knows best.