I have 'New Member syndrome' and am quite unsure about how to go about corrections (though I have tried looking at the various help sections!). The Chinese sentence does not appear to have been correctly linked to the European translations here (though I'm not enough of an expert on French or German to be 100% about those languages). The Chinese sentence implies the following meaning: "Wait, wait a second AND IT'LL BE OK/FINE". This isn't reflected in the English. How do I improve this?

Sorry if I ask, but are you sure?

In Chinese, it's conceivable that there are certain contexts where this phrase - 等一下就好 - might be best translated as, simply, 'Wait a while'. However, 等一下 (or 稍等 of 等等) by itself has this meaning. The final two characters - 就好 - imply that there will be a positive result to the waiting - ie. by waiting, things will be improved/solved/dealt with etc.

Yes you are right. Literally, "就好" means "will be fine" in Chinese but the whole sentence means, "Wait, Wait a second."
However, you can simple say "等，等一下。" or "嗯，等一下。"

Yes, it implies a positive result but I could not think of anyone asking others to wait for a bad result.

So it will be not necessary to unlink the sentences, am I right?

It's amazing how complex such a simple sentence can be! There is probably no 'correct' answer here, and Tsayng is obviously far more expert at Chinese than I am. All I'd say is that 等一下就好 makes me think of a mother soothing a child who has hurt himself (ie. 'it's ok, it'll get better in a little while'), whereas if you were asked to wait to see the doctor, the receptionist would probably say "请稍等" or "等一下，好吗" as a way of asking you to 'Wait a while'.

There's an argument to say this very simple sentence shows the great difficulty of translating sentence by sentence without a wider context. There are so many potential translations because of the scope of the Chinese word '好'. The sentence might mean: "Wait a while and [something] will be ready/fine/better/done/finished" etc. Maybe just 'wait a while' is the closest you can get without getting caught up in all the arguments, but it's not the best translation of 'wait a while'. 等一下 on its own would seem to be far more generally usable.

On a more general point, is the comment thread the correct place for these kind of discussions?

I do not want to be stubborn. I have to admit that the best translation here would be "等等" since the context is not provided. And the followings are the variations of the these Chinese sentence:
嗯，稍等。
嗯，等一下。
嗯，等一下就好。
Thanks for the comments and suggestions,anyway. I've learnt a lot from this translation.