Its no great feat to say chaos occurs at any scale; it is written right into the basics of the laws of thermodynamics. The universe's idea of orderly balance is really controlled chaos, with most objects attempting to achieve the lowest energy states.
I don't really think there needs to be a program or master plan as it were for controlling any of this however. Felarya is a dimensional entity that is joined with like entities. Based on the conflicts between entropy and energy wells, one could easily surmise that Felarya will only connect to areas of 'safe' coexistence. Dimensonal vortexes are more likely to connect with Felarya than the other way around, as they are going to be attempting to achieve lower energy states and Felarya is a potential energy well. If we assume Felarya's plane of existence is a dimensional ground, then objects will interact with it most of the time, with smaller probabilities of Felarya interacting with them. Most people see the random dimensional events as Felarya's fault (where Felarya is reaching out to them), but I see it being the fault of the parent dimension and it is just that Felarya exists in a well that makes it favorable for reactions (where their dimension is reaching out for Felarya). Highlighting on Hawking's paradox theorems for wormholes, we can then see that if anything, events are going to occur moments into the future and not the past, so if these moments would yield catastrophic balance shifts for Felarya, the guardians would have the opportunity to intervene and prevent it. Since these interactions are just the result of dimensional incongruities, any entity with dimensional control ability be they mage or guardian would be able to influence them; to a lesser or greater degree of course depending on ability. This would more appropriately simulate Felarya's chaotic state, rather than assuming an entity (composed of one or many) is responsible for direction and control. The above also lends more credence to the creatures that live within the dimensional voids in particular areas of Felarya, as with your proposal these creatures would also need to interact with the 'program'.
'Stable' portals, such as the one at Ur-Sagol, tend to be advanced designs with some sort of 'programming' that allows them to function in their listed ways. I see them moreso in your idea than the entirety of Felarya. Maintaining a permanent energy potential between an infinite number of areas as the Ur-Sagol portal does would require some sort of energy well of its own, which we could theorize to be it's own entity in and of itself, basically a chaotic intra-dimension that could be likened to Hajime Kanzaka's Dark Golden Lord in the Slayer's anime series. This entity would control the energy potentials of the intra-dimensional mass/energy complex much like the locks of the Panama Canal to allow for transportation of subjects using the portal. Though we could also achieve a similar effect without energy potentials by using the principles of quantum entanglement, in the case of the Ur-Sagol portal this would mean that the Ur-Sagol portal would have to have had someone generate an infinite number of endpoints in a one-to-infinite connection that can cycle through and allow those using the portal to reach their intended destination. Since that would be much more difficult (on the line of 'highly and statistically improbable' even in the technobabble arena) and time consuming to do, not to mention would limit the number of outgoing points and make the 'you travel to where your mind wants to go' highly improbable to achieve, I think any dimensional entity that created the Ur-Sagol portal would instead lend itself to the potential well design instead. However, the smaller one-way portals used by other cities and individuals could easily fall into the entanglement design instead, since both magic or technology could easily be employed to generate the required effects and they have a very finite number of destinations. Furthermore, simple designs have the least opportunity for malfunction, as the lesser amount of components equipment have in construction the lesser probability that a failure of any one of those components would lead to catastrophic failure of the entire device.