I think, translating complete sentences definitely has its merits. Learning from examples can be very good.
It can also be a good way to distinguish between different nuances of the same thing.
However, maybe we should discourage asking for translations requests of more than one (or a few) sentences, as long as they are not all examples to ask about a specific thing.
As for answers, I would consider an answer good that does not simply give a single translation, but go through the parts of the sentence and explain why and how it is used.