The early messages between home exchange members are very important in enabling both to ask and answer questions as they occur (and generally get a feeling on their compatibility) without, at this stage, a firm commitment to exchange. Email has speeded up initial communication greatly but time and care should still be taken to minimise any possibility of misunderstandings later on.
Once both parties to an exchange agree to swap homes, they will continue to correspond to finalise all details in the run-up to the exchange. If flights are involved, it's a good idea to book tickets at the same time and share confirmation of the bookings - this is a reassurance to both of a mutual commitment to go ahead with the exchange. At this stage, it's definitely unacceptable to cancel an agreed swap (barring unforeseen circumstances such as a death or serious illness in the family).
So, back to the topic of broaching 'awkward' questions. Anything that could (but shouldn't if raised with sensitivity) potentially be taken as a negative comment on an exchange partners' home or area comes under the 'awkward' category. It's best that any such questions are addressed as early as possible rather than after an exchange has been agreed and plans are at an advanced stage, or worse, not addressed at all and possibly causing last minute wobbles.
If, for example, you live very close to a major airport or busy road, pre-empt any likely concerns such as noise or pollution by addressing these in your listing (plus, of course, including photos so that potential exchange partners have a good idea of your home and location). You may be used to noise levels that visitors from quieter areas might find too disturbing. But, perhaps your home is triple glazed or bedrooms are away from the road, minimising the impact of noise. As with all aspects of describing your home and area - be honest!
Another cause of concern might be real or perceived levels of crime in an inner city area. Although living in a rural area is no guarantee that exchange guests won't ever be victims of crime, country dwellers may feel apprehensive before visiting a large city where crime (or perceived crime levels) are a worry.
Even if you live in a rural idyll, the bull in a field next to your garden could seem very menacing indeed to a city dweller who might be afraid to use public footpaths near your home unless reassured this is safe. Or an area may be prone to natural disasters such as tornadoes or floods. There can be 'what if' questions wherever you live or exchange to.
If your potentially awkward questions have not been addressed in your exchange partners' listing, go ahead and ask about any concerns you have (in a courteous way of course). And, if you are on the receiving end of such questions? Don't take it personally but rather address concerns honestly and with practical suggestions. After all, you live in your area and, if there are any reasons for taking sensible precautions (whether against pickpockets, menacing bulls, tornadoes, noise, travelling by public transport, etc, etc), pass on the benefit of your experience. Ultimately, though, the adults in exchange parties must take full responsibility for their own, and their children's, health and safety while taking part in an exchange.
Over to you, experienced home exchangers - how have you handled any tricky questions that have cropped up when arranging an exchange?