Yes, my nephew oy needs to say the word fire to destroy his enemies. Just like the two witnesses do. Fire proceeds from thier mouths. Fire proceeds from my nephews mouth and it does the same thing.
Yes, your nephew can speak the WORD fire from his mouth, but literal FIRE does not come forth from his mouth. Also, I would assume that your nephew is someone who follows someone else's order, or in the case of the US military, that order would have to come from the President as the Commander in Chief.
Is your nephew some renegade military grunt who needs to be reported to the proper authorities for launching military weapons against his enemies without the proper authorization?
As far as the two witnesses are concerned, if you can't even understand how your nephew follows orders; orders where a judgement has been made, then how should you ever understand the two witnesses?
Even Jesus said the following...
John 5:30
I can of mine own self do nothing: as I hear, I judge: and my judgment is just; because I seek not mine own will, but the will of the Father which hath sent me.
John 8:16-18
And yet if I judge, my judgment is true: for I am not alone, but I and the Father that sent me. It is also written in your law, that the testimony of two men is true. I am one that bear witness of myself, and the Father that sent me beareth witness of me.
Just a little friendly advise. Your crusade against the two witnesses has become excessive and it appears to be consuming your thoughts. It doesn't appear that you are taken all things into consideration, but rather have become fixated on what you want to judge as being evil, making yourself a judge of the law, and a judge over God's judgement.
I will agree with one of your sentiments, and that as followers of Jesus, He did not tell us to call fire down from heaven as did Elijah. In fact he rebuked his disciples for suggesting such, saying know you not what spirit you are of? (Luke 9:54-55)
The two witnesses are given the authority, you should accept it at that, and let it go for now. Take a breather. Think about something else for a while. Think about the sign of Jonah. As your nephew was most likely following orders, consider the prophet Jonah.
Jonah, as a prophet and witness of God, was given an order by God to go to Nineveh and warn them of their coming judgement and give them a chance to repent. But, Jonah didn't want to go to Nineveh, he went and hid instead, hoping for the city to be burned with fire in judgement. When Jonah finally arrived in Nineveh and the people repented, God spared the city and the people. But Jonah didn't believe God, so he went and camped out upon a hill, waiting for Nineveh to be destroyed. You should go and read the last chapter of the book of Jonah and see what became of Jonah's end.
As Jesus said there shall be no sign given except the sign of Jonah the prophet, then consider for yourself how Jonah wanted for their judgement, but then didn't believe God when he had forgiven them.