RE: My personal belief is, that when you consider a theological point, there can only be one modern English word that could properly convey what the author was intending to get across as to the reason they wrote the letter.
I am a Christian with a strong belief that the Bible is God's inspired word and inerrant. I am part of a small group of men who have been training pastors in two Latin American countries last year. That being said, Biblical Theology dictates, as you have implied, that original context provides a strong direction for determination of original meaning. Because the "real" meaning of the text is the original, inspired, meaning. It will be the meaning that would have been understood by the original intended audience.
One of my favorite phrases from a Biola class on hermeneutics is: The Bible is not written to you!
That same professor continues by pointing out that even though the Bible is not written to you, it is certainly written FOR you!
It was written to people who existed in a different culture, in a different land, speaking a different language, living at a different time. Thus, the expositor must make an attempt to "translate" him or herself back to that original context.
Fortunately, most of the important doctrines do not hinge on this contextual view. For instance, Christ saying "I am the way, and the truth, and the life. No man comes to the Father except by Me." [my paraphrase], transcends the cultural and temporal divide, for the most part.
Getting back to your original stipulation that there can be only one English word which conveys the proper meaning stands context on its head. The Bible was never written in English. There is no guarantee that all Hebrew and Greek words can be properly translated into one particular English word.
Even if one finds a very strong correlation, there is still the possibility that a modern English reader will pick an English variant not intended by the translator.
I would advise you to spend some time in a few technical commentaries that deal with the Greek and the Hebrew. The WBC, World Bible Commentary series, comes to mind. You will soon find that these people with a lot of experience in the original languages struggle to find the appropriate words and phrases for translation and will many times supply variants which will have followings among others who also attempt to achieve faithful translations.
Further, to trivialize the process into "word for word" shows a naivete about how translations can be done. I read some French. There are many cases where one French word must be translated into many English words and vice versa. Certainly, word order cannot be preserved without doing grave damage to the meaning.
Pastors who pay attention employ the NASB when they want the closest word for word translation. They have to put up with it being slightly stilted. Our church, which is a Bible church with a slant towards Baptist theology, uses the ESV in the pews. It is a modern variant with an attempt to keep to original word meanings.
You may be interested to learn Dr. Frank Logsdon, the former chief editor of the NASV, later disavowed the NASV in favor of the KJV due to serious doctrinal issues resultant from using Westcott-Hort derived texts. The same problems exist with the ESV.
Some of many example verses where the significant doctrinal issues arise (compare KJV or other Majority Text-based translations to the NAS, ESV, NIV or other Minority Text-based translations) include:
Matthew 6:13, 9:13, 17:21, 18:11, 23:14, 27:35
Mark 7:16, 9:44, 11:26, 15:28
Luke 4:4, 4:8, 11:2
John 1:14, 3:15, 3:16, 6:47
Acts 8:37
Romans 8:1
There are many, many other passages (both Old and New Testament) where the difference in the underlying text dramatically impacts doctrine, and that does not even factor variation from translation methodologies.
If you would like a more extensive parallel comparison, feel free to DM me.