Romans 11:4-6 - Does this mean, as it seems to imply, that God picked out some folks back in Elijah's day an kept them from sinning? And that, in Paul's day, God had picked out some Jews to be 'His'? The implication, at least in my mind, is that perhaps even those who had been picked didn't even know they had been picked. I guess that's not necessary from the text, just my mind's interpretation. Still, it seems to say that God sort of said "Just in case, I'll set aside these folks to be my people." I have to remember, though, in these passages that God sees the entirety of time in one viewing. He can look & know who will respond and choose them before they actually do. I also have to remember that Paul's point in Romans was not to explain God's choosing us and how that happens, but to explain that Jews and Gentiles are alike and that we are saved by God's grace. Still, trying to sort out God's choosing and man's choosing makes my head spin.
Romans 11:7-10 - I think that this can apply to all of us. If we are not earnestly seeking God, anywhere and in any way, our eyes may not be able to see Him or our ears hear Him, for our preconceived notions about who He is or where He is will blind and deafen us. I certainly think that my believing that I had God all figured out has blinded me to a greater vision of His being and His glory in the past.
Romans 11:17-24 - These verses clearly show that our choices influence God's choices in grafting us to cutting us off. God has not made it purely His choice alone, He has left it to us as well. The bottom line remains - had God not chosen to reach out to us, we would be doomed.
Romans 11:29 - "For the gifts and the calling of God are irrevocable." - ESV. How cool is that!