Actually, your paper sounds quite interesting, since I've always been fascinated by the inner workings of the Sassanids. It always seemed to me that the Sassanid empire is often glossed over when it comes to both Roman and Islamic history courses, since their peak correlates with the decline of Rome and their fall occurs near the beginning of the spread of Islam. They're nestled right at a natural division of time periods in the Near East and Iran (pre and post Islam), so they're easily overlooked which is shame, since they left a large and lasting impression on both groups.
As far as sources for our discussion, Ammianus Marcellinus is probably the best and most common primary source, but take a look at this link:
http://www.academia.edu/329117/Rome_and_the_Sassanid_Empire_Confrontation_and_Coexistence. It mentions several of the same points that my professor did with better sources than I'll be able to give you.
With the rise of the Sassanids and especially before the reign of Khosrau I, power became more centralized within the court and person of the Shahanshah than it had previously with the Parthians. However, the Shahanshah was still very dependent on nobles for support, and one of the ways a new ruler would "legitimize" himself in the early part of his reign was to go to war with the Romans.
Most times these were little more than border clashes and large raids, but the best examples I have of this are from the reigns of Ardashir and Shapur I and II. They all pursued very aggressive policies towards the Romans early in the reigns, possibly as a means of gaining support and focusing the upper castes energies outward. Also, going from memory, I seem to remember reading that it was very common for later Shahanshahs to pursue similar courses.
Now, most of our discussion was definitely conjecture, but I do believe it is a very interesting point and definitely within the realm of possibility. However, it also highlights another problem with studying the Sassanids. A severe lack of primary sources; most all the sources I remember working with were either Greek and Roman in origin, or used the Greek and Roman sources as their foundation, so you have to be careful what conclusions you can draw from them. There's just not enough information from the Sassanid point of view to really prove anything, but then again, this is a problem for most all of ancient history.
Anyways, I'm just rambling now, but I am interested to hear what you think since you appear to be very well versed in the area. As a former history major who focused on Roman and Islamic studies (I double majored in Biology as well and have pursued a career in science instead), the Sassanids were one of my favorite topics, and it always pleases me for them to get the "credit" that they deserve.