"On the other hand, I will say concerning a nation or kingdom that I will build and plant, but if it does evil in my sight, not listening to my voice, then I might change my mind about the good that I had intended to do to it" (Jer. 18:9-10). The contrary divine thing might happen, too. YHWH may have decided to build and plant a nation, but if that nation goes bad, then building and planting might become annihilation after all.
The lesson of the potter is clear enough. YHWH is sovereign over Israel as the potter is sovereign over the clay and is able to do whatever she determines to do. The chief difference, and it is a most important one, is that Israel, we, have the chance to do better, once we know that YHWH is sovereign.
Nevertheless, there is a large problem here theologically, I think. If I do better, then God will be nice with me? If I do poorly, then God will rebuke me for my evil? It is of course not always so easy as all that, is it? The book of Job made that crystal clear not too many years after Jeremiah's prophecy. Then what to do with this old and disreputable theology? Is it all to be simply thrown out?
Perhaps not. Focus instead on the pot, the common easily cracked pot. We are then the cracked pots of God. Paul redeemed this image for me in 2 Corinthians 4:7 when he said "we have this treasure in clay jars," in effect the crackable pots of Jeremiah. And what does Paul mean by "this treasure"? This treasure is the fact that we do not "proclaim ourselves" but focus only on God and on Jesus Christ whom God has sent. In this light, the parable of the pots is less about the ability of God to respond to our good or evil acts, than it is about God choosing us to contain the gospel, despite the fact that we too often do evil acts and despite the fact that we are all finally cracked pots! Nevertheless, God has chosen us to be vessels of God's gospel. We are God's cracked pots, and that is a grand and wonderful and mysterious thing indeed!