Well then you must think that God is offended by any type of announcement regarding activities after church or outside of church.
As a part of worship, yes I think it is inappropriate. That's why we have all our announcements at the beginning and at the end, so that we don't interrupt worship in song and message with announcements. We have announcements, then we begin worship. We sing, pray, sing and take the offering, preach, pray, and sing. We do these things because God has commanded each one of them. We have the ordinances periodically as well, again, because God has commanded them. We do not do anything in worship that God has not commanded us to do.
However, these announcements generally do serve a body function in that they announce fellowship events, Bible study events, etc, all of which are legitimate biblically prescribed functions. The pledge of allegiance does not fit into any of those categories. BTW, the Pledge of Allegiance leads people to lie in church because we are not "one nation under God" with "liberty and justice for all." Many in our country are not under God, and they do not have liberty and justice. So we are in effect asking people to tell lies as a part of worship to God.
Do we have a kind father in heaven or some stern tight-lipped taskmaster?
Yes we do. He demands perfection, and everyone who doesn't have it goes to hell for eternity. It is far more austere than you can imagine. In fact, because of his perfect demands, he killed his own son. And he did that because of his perfection and our sinfulness. So he is a Father who is a stern tight-lipped taskmaster. He tells us what to do, and then he did it for us. And now he calls us to walk worthy of it.
Do you also think that our Lord is angry when we ask His blessing on our country?
No, that it a biblical command (1 Tim 2:1-2). Saying the Pledge of Allegiance is not.
Is singing God bless America a sin?
Not really, but it is inappropriate for gospel worship since it doesn't have anything to do with the gospel, and divides people on the national lines that Jesus died to erase.
God has blessed us greatly here. I think that thanking him for those blessings and asking his continued blessings on our country are pleasing to him.
I completely agree. In the Bible, these things are commanded as a part of worship -- to praise God for his mercy to us and to pray for continued mercy.
That is exactly my point: We do these things because God has commanded us to. He has told us that this pleases him. He has not said that about pledging allegiance to a political entity.