Hi Relaxation,
Many of your questions are about “comfort” choices or preference issues which are very subjective and can only be answered based on your own personal testing or experience and don’t really have an answer with the degree of specificity that you may be looking for.
You can read more about the many variables that can affect temperature regulation and the sleeping temperature of a mattress in post #2 here. In general terms … latex is the most breathable of all the foam materials but isn’t as breathable or temperature regulating as most natural fiber materials. The layers that are closer to the sleeping surface will have more effect on ventilation and moisture wicking and temperature regulation than the layers or components deeper in the mattress.
Surface modifications such as convoluting or sculpting will affect the softness of the sleeping surface and to some degree the airflow as well. There is more about convoluting in post #2 here and in reply to question 4 in post #2 here and in post #4 here.
These types of “comfort” questions that are connected to whether a mattress is a suitable choice for you in terms of PPP (Posture and alignment, Pressure relief, and Personal preferences) can only be answered based on your own careful testing in a showroom (hopefully using the testing guidelines in the tutorial), your own sleeping experience, or with more detailed conversations with a knowledgeable retailer or manufacturer that sells a mattress or topper you are considering who will be your best source of guidance about the mattresses or toppers that they sell (see mattress firmness/comfort levels in post #2 here once again).
The list of better online sources I’m aware of are linked in the topper guidelines I’ve already linked and there is also a link to some of the better return or exchange policies there as well. They will also all provide information about their exchange or return policies either on their websites or with a phone call if any of the information they provide is unclear. I’ve also linked the better options or possibilities I’m aware of in your area in my previous replies. I can certainly help you narrow down your choices, help eliminate the worst ones, act as a “fact check”, or help you with “how” to choose but only you can decide on “what” to choose and I don’t make specific recommendations or suggestions about specific mattresses, toppers, materials, or companies or about which specific topper may be the best match for you on your mattress in terms of PPP or all the other parts of your personal value equation that are most important to you because you are the only one that can make these types of choices based on your own personal preferences and criteria.
Phoenix