A Calvinist website attempts to list out proof of Calvinism from texts other than Romans 9. From Triablogue:
10 The Lord brings the counsel of the nations to nothing;
he frustrates the plans of the peoples.
11 The counsel of the Lord stands forever,
the plans of his heart to all generations.
15 he who fashions the hearts of them all
and observes all their deeds.
On the other hand, the counsel and the purposes of the Lord endure forever. Here we find the verb “stand firm, endure” repeated. As the Lord’s creation stood firm at his decree (v9), so his counsel stands firm forever (v11). It cannot be shaken or interrupted by the antagonistic plans of the world. As the sage says, “There is no counsel, no wisdom, no plan against the counsel of the Lord” (Prov 21:30).. And to make his plan stand, as the psalmist says, “He brings to nothing the plans of the nations.” The certainty of the plan of the Lord is not temporary–it is eternal. This is stressed by “forever, to the farthest time,” and reiterated in the parallel colon that affirms that the purposes of God’s heart are “until endless generations.” The plan of the Lord can be trusted completely because it is carried out in faithfulness.
The first thing of note is that three verses are skipped in the middle of the quoted text. Interestingly enough, two of these verses are wholesale rejected by Calvinists:
Psa 33:12 Blessed is the nation whose God is the LORD, The people He has chosen as His own inheritance.
Psa 33:13 The LORD looks from heaven; He sees all the sons of men.
Psa 33:14 From the place of His dwelling He looks On all the inhabitants of the earth;
In Psalms 33, the psalmist presents God as dwelling in the heavens, watching men, looking down on men to see what they are doing. The idea being presented is that God actively watches mankind. In this regards, God sees what men are planning and God thwarts them (v10). The idea that God is actively monitoring and responding in real time to ensure His work is not destroyed is not a Calvinist theme.
Later, the text explicitly states that God gives special protection to those who worship God. God is said to save them from death and keep them alive in trying times:
Psa 33:18 Behold, the eye of the LORD is on those who fear Him, On those who hope in His mercy,
Psa 33:19 To deliver their soul from death, And to keep them alive in famine.
This is also not a Calvinist theme. If God had planned out eternity from before time began, from what death are people being saved? No, the concept is that when God sees His children in trouble, God intervenes and saves them. The entire section of Psalms 33 is about God’s dynamic relationship to mankind. God has plans and purposes. God will fulfill those plans. Thus God monitors human beings such that they do not thwart those plans.
This is a very Open Theistic text.