Security or preservation, also deliverance, are the most 'literal'* meanings for the Greek word 'soteria'. Therefore, when Darby in his Bible translation chooses to use the word 'preserve' in 1 Timothy 2:15, he is interpreting 'soteria' in the more literal sense, the non-figurative sense, and this contributes to Darby's translation being a more literal translation of the Bible than the KJV and its descendants.
I would argue that the same prinicipal applies for the words 'ekklesia', 'episkopos' and other like ecclesiatical terms. The more everyday meaning of the word ekklesia, certainly at the time that the Bible was written was 'assembly' and for 'episkopos' 'supervisor' not bishop. I am not arguing that a translation should follow this kind of pattern. However, the concept of a 'literal' Bible translation has been much misused lately.
Certain translations which are today called literal translations, would be better called translations in the eccesiastical and theological tradition. They bring theological baggage to the Bible. It is fine to say that one should read the Bible without theological baggage, but how does one know to strip away the theology of the major English translations. Very few people these days approach the Bible after studying classical Greek for many years before reading the NT in Greek.
To be fair I am not sure that Darby did this either. One could rightly call his translation a non-ecclesiastical translation. What needs to be understood is just this. All translations belong to a certain human translation tradition; they are all interpretations and each one has its own baggage.
- limited to the explicit meaning of a word or text; "a literal translation" Wordnet
The ordinary, straight-forward lexical (dictionary) meaning of a word or expression. Sometimes used in contrast to a figurative interpretation, sometimes including figurative interpretation. from Ron Leigh
the ordinary or natural meaning of an expression, its primary meaning, in contrast to its figurative or secondary meaning Bible Centre