Just to make sure I'm understanding: Repeated bruising (or prolonged bruising force) to an area can cause issues with the body's ability to heal itself properly. Dangerous implements (particularly thin, bendy ones, akin to a cane) should be off the table without a demonstration of how to properly use it (hmm. That could be interesting). Use lotion and/or topicals on any and all wounds, including abrasions, welts, and breaking of the skin. Unintentional breaking of the skin is a mishandling of the implement.

If this is all correct, I have a few more questions: Is breaking the skin (even once in a while) using an implement of spanking (or what have you) ever a sound idea?

Is it considered reasonably safe to leave red(or whatever color) marks via spanking (hand or other method) which can be seen for the next day or so?

Do these sound like really basic questions that I should already know? I don't want to be wasting anybody's time, I just want to make sure that he's comfortable that we're playing safely.