All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His Slave and Messenger.
The Barelwi sect is undoubtedly a Sufi sect that is based on deviant beliefs and thoughts some of which lead to disbelief. For further information see Fatwa 87790. You have done well by keeping steadfast on the truth and avoiding this sect. We advise you to be gentle with your people and cooperate with your steadfast brothers in conveying the truth and teaching people goodness with wisdom, beautiful admonition and patience over any possible harm. The Prophet, sallallaahu ‘alayhi wa sallam, said: "By Allaah, if Allaah guides one single man through you, it would be better for you than possessing the red camels [i.e. the most precious kind of camels]." [Al-Bukhari and Muslim]
As for the Deobandi sect and their staunch support of the Hanafi School of jurisprudence, there is no doubt that a Muslim should in principle follow the evidence. This is the duty of the Muslim who is able to recognize the evidence and its indications, compare between the jurists' opinions, know the preponderant of them and act according to it. But a Muslim who lacks this ability is allowed to follow a specific School of jurisprudence, such as the Hanafi School as mentioned in the question. Yet, it is not obligatory on him to follow this School of jurisprudence; he is permitted to act according to the Fatwa given to him by a scholar who follows any School of jurisprudence, provided the scholar is righteous.
As for marriage, religiousness and good moral conduct are the considerable criteria for equivalence in marriage, and the matrimonial guardian should not reject a suitor merely on the basis of his race or the like. Nevertheless, they have the right to decline your marriage proposal to their daughter as it is not an obligation on them to accept your proposal even if you are religious, and have good manners. However, there is no harm in writing a letter to the girl in question in order to explain to her your desire for marriage to her or anything else which does not contradict the Sharee‘ah. Perhaps it would be preferable if you did this through someone you trust of your female relatives.
It seems that your marriage to this girl involves many obstacles, in addition to your need for some time to complete your marriage. Therefore, we suggest that you wait until you finish your studies, and perhaps during that interval you will find a righteous girl from your family or from people who do not turn down marriage proposals on the basis of race.
Allaah Knows best.