I have missed the point that you are trying to make in your question. Are you asking about the dangers of swapping partners, as you want to try out this lifestyle? Your questions are obviously lifted from some passage from the Net.
Swapping is a lifestyle that once started is difficult to stop. You will need to think about the consequences very seriously. If you think it is a one off thing, it is not. You will keep experimenting.
There are some dangerous pitfalls in this lifestyle. Jealousy is one of them. At some point, if you are all together, you may feel that your wife is paying more attention to her partner than to you. Or you may feel that she is moaning louder with her friend. This may create a rift when you are both having an argument and one of you may bring up this topic.
There is often a tendency to cheat. Swapping may lead to one of you meeting your swap partner without the knowledge of your own partner. The problem with swapping is that there are more variables which are difficult to control. One can never predict how emotions will play out and in spite of the best intentions things can go awry. However this does not imply that the experience cannot be mind-blowing.
You first need to have your wife's consent in clear terms. Do not presume that she will agree after you have made all the arrangements. Finding suitable swap partners is never easy and takes unbelievable effort and persistence. It is almost like a marriage portal, where you see and meet your future marriage partner. You will need to decide at whose place you will swap or will it be at a hotel? Imagine the embarrassment if there is, a police raid and the explanation you will have to give!
Whatever you decide, do not do it out of compulsion. And always insist on using a condom.