Our great scholars who are Maraaje’ of Taqleed have studies all the Hadiths regarding marriage including this Hadith mentioned in your question and gave clear verdict that marriage between Mo'mina and Mo’min is allowed with out the condition of being Sayyed or not Sayyed. Great Sayyed Ulama have given their Sayyed daughters for marriage to non Sayyed Mo’mins like Ayatullah Khomeini who gave his daughter to Shaikh Eshraqi, Ayatullah Sayyed Muhsin Al-Hakeem who gave his daughter to Shaikh Hasan Najaf, Ayatullah Gulpaygani who gave his daughter to Shaikh Saadi and many other great Ulama.

In some countries culture such marriage is not accepted, but culture can never change the Sharia of the Prophet (SAWA) and Ahlul Bayt (AS).

Wassalam.

Umm Habiba (Ramla Bint Abi Sofyanwas) was married to Abdullah Ibn Jahsh who migrated with her to Habasha Abisonia,  then died there. After her Iddah, the Prophet (SAWA) sent a proposal to her. As  a daughter of Abu Sofyan who was a big enemy of the Prophet Muhammad (SAWA) and sister of Mo’awiya ibn Abi Sofyan who was the enemy of Imam Ali (AS). I could not find any praise for her in our books like praise for wives like Umm Salamah or Mariah Umm Ebraheem. If she really celebrated the death of Mohammad Ibn Abi Bakr, who was a sincere follower of Ameerul Mo;mineen Ali (AS), that should be enough for us to know her association with her brother Mo’awiya.

Allah Knows the best.

Wassalam.

It is permissible to receive money from the government for studying expenses knowing that the government will take it back in instalments from your future salaries.

Wassalam.

Yes it is permissible for the organizers in the sport tournament to receive a prize if the prize organizers allow that. 
‘Wassalam.

Referral Code is understood to be used by the person himself unless the issuers allow otherwise. We are not allowed to use referral code of others with out their permission and the permission of the issuers of the Code.

Wassalam.

You as a Muslim should be very careful not to be involved in unlawful business and your software should not be used in any type of transactions which are not permissible in Islam. Binary options are considered by many as a form of gambling rather than an investment because of their negative cumulative payout. 
'Wassalam.

We don't need nor require to watch all the materials of the signs of Allah on You Tube or Internet. We watch whatever we can or need. Wassalam.

It is Not necessary to perform Sajda Sahw for just not following Tajweed rules in Salah. You should recite as much as you can as in Qira'ah and as in Tajweed.

Wassalam..

If the Najis fabric is from pork or dog or non Halal animal skin, then there is no way to clean or purify such material. If the Najis fabric is not Najis Al-A'yn, then you can wash it with water and make it Taahir.

Wassalam.

None of the things mentioned in your question can be concrete evidence of Sihr or black magic etc. Ahlul Bayt (AS)'s teachings to avoid all types of Sihr, black magic and any harm is to recite Ayatul Kursi, Sura Falaq and Sura An Naas along with Sadaqa and Du'a. You then need not to worry about any thing as far as you are protected by these Quranic verses.

Wassalam.

Tolerating the assault and harm from your relatives for the sake of Allah (SWT) is a type of Jihad in the way of Allah. The Holy Ahlul Bayt (AS) have tolerated great pain from some of their own relatives and taught Muslims how to deal with the relatives in all the circumstances. You should maintain good contact with your brother despite his assault on you and avoid any word or behavior  which harms your relationship with him. You should also apologize for any wrong you said to him in anger.

Wassalam.