What am I disobeying? My own wrong impression that God wants me to pray for someone? Or are you saying God did impress upon me the urge to pray and followed it up by causing me to disobey? Either way, what am I responsible for?
I'm saying that God commands us to pray for people--all kinds of people. If you don't pray for the salvation of someone who comes to mind and who needs to be saved, then you aren't obeying God's command.
And God is not the agent or direct cause of any disobedience. (Of course, he's the first cause of everything.) God's eternal plan (or ordination) is not the
efficient cause of anything. The things in his plan are brought about by more immediate causes or agents, like, in this instance, your disobedient heart. In this case, God's role in this is one of inaction, rather than action. He permits you to disobey him.
What are you responsible for? The inaction of your disobedient heart.
Was it possible for Paul to disobey?
Was it certain that Paul would obey? Yes. Was it necessary that Paul obey? No. Paul was given the choice; both options were real options; there was only one that Paul would actually choose.
Is it as if God wrote a script and He is one of the characters His play?
Well yes and no. That's not a bad analogy, but like any analogy it falls short of the real deal. For one thing, actors in a play are just playing a script. People in the world are acting and reacting genuinely to the circumstances around them. They are truly experiencing everything. They don't know what the next moment of the play brings.
What I can say is that God has a plan, and the world runs according to his plan, and he interacts with his world--arranging circumstances, moving hearts, preventing things, permitting things--so that the plan comes about. He is never the immediate cause of a sinful action, but sinful actions come about by way of God's permission.
Yes, I believe God has an eternal plan. No, I do not believe God's plan changes.
Okay. So what things are included in God's plan that never changes?