When you have a proposition without an explicit quantifier (and it’s obviously not singular) then you have to choose between taking it as universal and taking it as particular. If you’re speaking to someone, you can of course ask him to clarify his meaning; likewise, if you’re emailing or texting or phoning – this is a point you have yourself correctly noted. However, if you’re not in contact with the speaker or writer then, unless the context unambiguously requires you to take a proposition universally, you should take it particularly, as that commits the utterer of the proposition to a more defensible position. [See my brief discussion of the principle of charity under the ‘All or some’ topic.]
In the particular example you discuss – “Men are sometimes dishonest” – not only is there nothing in this proposition considered simply in itself to suggest universality which, under the principle of charity, would be enough to take it as particular, but further, the adverb ‘sometimes’ gives you a further positive push in that direction.
Your third paragraph contains a ‘therefore’ which, as I hope you may come to see, is not strictly justified. There is a difference between one proposition’s implying another and one proposition’s being consistent with another. This should become clearer when we come to take a look at inference.
Finally, translation is an art, not a science. Your task in translation it to do your best to go from one language to another without semantic falsification or semantic addition. In most cases in our logic, the translation is straightforward; in a few cases, there is genuine room for disagreement.
I have found from experience that some of the problems people have with translation are retrospectively clarified once they move on to a consideration of inference.