You certainly sent me on a Summa T. search! (Only place I knew to go to for that topic.)
Clarifying what type of “miracle” is being considered seems to be critical.
I answer that, …So for a miracle is required that it be against the order of the whole created nature. But God alone can do this, because, whatever an angel or any other creature does by its own power, is according to the order of created nature; and thus it is not a miracle. Hence God alone can work miracles.
Reply to Objection 2. Properly speaking, as said above, miracles are those things which are done outside the order of the whole created nature. But** as we do not know all the power of created nature**, it follows that when anything is done outside the order of created nature by a power unknown to us, it is called a miracle as regards ourselves. So when the demons do anything of their own natural power, these things are called “miracles” not in an absolute sense, but in reference to ourselves. …….
Reply to Objection 4. Although the angels can do something which is outside the order of corporeal nature, yet they cannot do anything outside the whole created order, which is essential to a miracle, as above explained.
Again, it’s critical to clarify what type of miracle we’re considering.
Demons, angels and Saints exist in a non-physical state. They can affect us spiritually, but not physically, unless God performs a miracle. It is not within their own power to transcend their nature, with or without God’s approval.
I don’t think we know the extent of power God has granted to angels as part of their nature. If you know of any authoritative texts that address this topic, would you please let me know. You say they cannot affect us physically – can you give me the source for that statement? Aquinas didn’t address it in the sections I read (either the extent or the limitation over physical matter).
In regards to power over physical material, my own thinking is that it’s more that God has imposed limitations on their exercise of their natural powers over material elements (especially in the case of fallen angels who hate us). A Scripture passage I always find interesting is in Revelations:
Rev. 9:13-15 Then the sixth angel blew his trumpet, and I heard a voice from the four horns of the golden altar before God, saying to the sixth angel who had the trumpet, “Release the four angels who are bound at the great river Euphra’tes.” So the four angels were released, who had been held ready for the hour, the day, the month, and the year, to kill a third of mankind. It gives the impression that they have the power to kill humans (as we humans also have), but God restrained them.
P.S. I understand that as far as officially defined doctrine by the Church, there is very little - so most of it falls in the category of what we’re speakibg of probably falls into the category of being open to speculation