Firstly, you are wrong about taqiyya. This is the original meaning of the word but it has been expanded by SUNNI scholars to mean 'anything that advances the cause of Islam'. I will provide my sources once a friend returns a book.
Secondly, the Great Commission requires us to reason, discuss even debate but NEVER to advance via the sword (unlike Islam!!!)
Thirdly, no scholar throughout history has taken Jesus' 'sword' statement to be literal. He came to do spiritual battle with the forces of evil but if you read the entire New Testament, nowhere will you find a call to violence! The Bible needs to be read in it's entirety to find context for what can seem like unusual statements.
Fourthly, I have no complaints with the instructions of God to the ancient Hebrews. It was entirely appropriate under the circumstances. They lived amongst child sacrificing, black magic practicing, demonised tribes and God was wanting the Hebrews to separate themselves from those practices. If you understand satanic practice you would understand that children are demonised from birth and the call to kill all, was appropriate under the circumstances. (it happened once!). If you have a better solution, under the circumstances, please let me know!
You will notice, if you have read the Bible, that once the Hebrews established themselves in the land of Israel, they were entirely on the defensive. They never sought to expand themselves via the sword (unlike Islam).
We live in a new era under Christ. He has 'fulfilled the law' and we are no longer bound by it. It is a great guide for moral conduct but Jesus' example with the woman caught in adultery is one we should follow ("let he who is without sin, cast the first stone).