I believe the question was asked quite clearly.
Your answer: "I know some who believe much of the reformed faith, but who still have doubts concerning the salvation." does not address the question.
"believe much of the reformed faith" does not equal "convinced of the validity of the tenets of Calvinism".
"have doubts concerning their salvation " certainly does not equal "assured that they are not part of those chosen few"
Do you not think that the evil one attacks all God's children? Not sure what this has to do with anything.
You ignored this part:
If we can be assured of our salvation because of predestination, can the opposite be true of our damnation?
OUCH!
You would be correct in stating that, not all of the Reformed Movement believes in all of the tenets of John Calvin.
The problem is in the labels, whether it be Calvinism, Arminianism or what ever. A "label" is just a quick way to say you are aligned with one view or another. It does not necessarily follow, that you believe every aspect of that view. To lump individuals into a particular "label" is like saying all human beings are exactly the same in every aspect.
What is really important here, is that we, as believers, STRIVE to obtain the TRUTH from the Holy Word of God. Bible Commentators can be helpful in our studies but they too, are STRIVING for the TRUTH of God's Holy Word.
To answer your last statement, about assurance... YES, we can be assured that all of whom God saves - ARE SAVED and ALL of whom God does not save - will go into condemnation. The Sovereign choice is the Creators - not the creation. Those who are saved - love God's Sovereignty in all things. Those who still lack Grace hate God's Sovereignty.