Does this PhD make sense or just another religious zealot's fear?

Yes, Sgt Spencer Sikder, the article on Aquinas makes sense. It is interesting that we think of the Good Samaritan and we believe he was representative of all Samaritans. Such is not the case. The Good Samaritan was the charitable exception, not the rule. Charity is a virtue to be practiced by individuals, not mandated by governments or fanatical groups. If we do not have freedom of choice, we do not have the freedom to act charitably, or to profess a creed freely. All religions have their zealots. It's time for Muslims to stand up and affirm the natural goodness of all people of good will. When American Muslims of good will make such a stand with their neighbors, the world may begin to believe in the goodness of Islam. Until such time, we as Americans have an obligation to protect our own, as did the Maccabees. There is credible evidence to suggest that there may be wolves (terrorists) dressed as sheep among the Syrian refugees.

Interesting question Sgt Spencer Sikder Dr Taylor Marshall posts a dichotomy Are We Good Samaritans? or Are We Good Maccabeans?
Personally I prefer to be a good Samaritan as an individual. The Samaritans were hated by the Jews yet the Good Samaritan tended to a wounded Jew is Christ's parable. The Maccabeans on the other hand fought the Roman's they saw as oppressors of the Jews.
The Catholic political theology of Saint Thomas Aquinas may help us with this question:
"In the Summa theologiae, Thomas Aquinas places politics under the civic virtue of patriotism which is itself a sub-virtue of justice. Our discussion is ultimately not about “politics” but the virtuous duties of justice toward God, our families, our nations, and all of humanity (in that order).
For Thomas Aquinas, all political human laws must be: 1) in accord with reason; 2) published or promulgated; 3) by rightful political authority; and for the common good. If a political law is lacking in any of these four attributes, it is for Thomas, not a law at all.
Muslims explicitly affirm that Muhammad is the Last Prophet of God.
Muslims explicitly affirm that Our Lord Jesus Christ is certainly not the Son of God.
These two Muslim affirmations place all Muslims in implicit or explicit theological contradiction with Christians who profess Jesus Christ as the Son of God and consequently conclude that Muhammad was a false prophet.
For Sunni Muslims (the majority of global Muslims), the mandate to erect Sharia law in every human government is a doctrine of faith. Muslims must in accord with their conscience pursue this theological belief that Sharia law must be promulgated in every human society (England, France, Poland, USA, Mexico, etc.)
So how does this apply to Refugees from Islamic nations?
When we move through the logical points above, we begin to discover a few logical conclusions:
Muslims are bound by conscience to erect Sharia law in your nation. This is a bad thing for baptized Christians. At best it means being taxed at a higher rate (the Muslim jizya tax for Christians). At worse it means death.
If you live in a democracy, a 51% political Islamic majority will allow “we the people” to promulgate Sharia law. They are following their conscience and religious beliefs in this matter. They will do this just as they have done in any other community where they captured the majority (Mecca, Palestine, Egypt, Syria, etc.)
It is a duty of of justice for Christian people to strive to prevent the promulgation of false laws (i.e. those contrary to reason or the common good). Christians are called to be politically active and advocates for the common good and natural law.
While we have the Christian duty to care for the refugee, the sick, the victim, and the injured, we have a greater common duty by justice to preserve the state of law and our religious liberty first and foremost.
We see this principle in our Scriptural readings. When it comes to the Samaritan, he rightfully cares for the victim. However, when it comes to the nation and the threat of terrorism (Seleucid Greeks), false laws, and the danger of our children, military, and civic peace, we (like the Maccabees) are politically obliged to resist, protect, and expel…for the common good."
While the argument is somewhat simplistic I tend to agree with Dr Taylor Marshall that a nation can not logically of feasibly play the role of the good Samaritan. It does not necessarily follow that the nation should adopt the position of the Maccabeans who were underdogs against Rome. The USA is in no way an underdog in the case of the Syrian refugees.