Oh goody! You're asking some excellent questions. I'll lend my experience if it will help.
"Aura"
You're describing what most people call "aura." Unfortunately, this term has too much baggage and is usually only prescribed to living beings. But it is everywhere. If it is being seen around a physical object, then when the the physical object is moved, the "aura" will take a little bit longer to move with it. Which, noticing that "delay" alone contains tremendous amounts of insight into "time" and higher planes.
I just tried focusing and noticed the delay. Would this also describe how a leaf, when torn, retain its aura? (What do you think of Kirlian photography?)
I've never torn a leaf and watched how its aura changed. I became aware of Kirlian photography around the same time in my progress as you, but not enough to comment on it. I soon lost interest in it because the profound depth and breadth of meditative phenomena was so absorbing and fulfilling.
"Tracers"
Anyway, this "delay" causes a "tracer" effect (another term with baggage.) If you absorb into it enough, you'll see the most glorious light everywhere. It is quite profound the first time. I just taught a couple people how to see, or rather, notice "aura" this last week.
I see streaks of gold or purple (mainly purple) from my body. But mostly when the visual charism seems to appear, my vision itself becomes obscured by light. Is this normal?
The "aura" is, in my experience, the visual charism. As one absorbs deeper into it, they begin to see higher planes, which are experienced as brilliant light. As I mentioned in an earlier post, if I go to bed at 2am, I will almost always be blinded by light as I enter sleep. No, it isn't normal. It's extraordinary. But it's nothing to worry about

Learning to See "Aura" and Implications of It
One took an hour to learn, but had too much fetter of "skeptical doubt" and so is not convinced yet. The other learned in less than a minute, and happens to be my fiance--which was very revealing. It is amazing just how much one can know through what I guess I would call "holistic" insight. Meaning that one can see the big picture and thus understand the context of the smaller pictures.
Hmm, I understand that one can use the visual charism as a meditative object, but I was wondering if developing this skill is useful to conduct? For example, looking at a person's aura and determining the right words to say, right actions to take, etc?
I don't spend much time on developing the ability to "read" aura. I rely primarily on the intuitive insight stream and critical thinking for that. In my experience, it's faster and deeper. However, I have found attempting to "read" aura for friends has initiated streams of insight. But, they weren't "small" insights like "your color is purple, you must be spiritual." I tend to use the intuition as guide as to questions like "should I learn to read aura?"
Charisms as Refuge
Perhaps this could be one of the new "charismatic refuges" you use during certain situations, or should you find yourself unable to overcome aversion with the intensity of another charism.
As always, I do not claim to be an arahant nor have more experience than others on here, such as Jhananda. So, take my words as they are, but not "my word for IT." I have sincerely appreciated your posts. I really have. Thank you.
I've also appreciated your posts, they've helped me too.
Sometimes I'm not too sure which charism I should meditate on. On some days I will use the visual, then I'll switch to tactile, then auditory. Is this counter-productive?
Bouncing Around the CharismsI experienced the same thing in your stage of experience. Personally, after I detected and intuited enough of the charisms to understand them in a more comprehensive way, I then chose one to stick with one main charism for formal meditation.
The Use of a Constant CharismThis is because I required a "constant" to enable observation of the stage changes. It's sort of like driving at a constant speed and watching cars pass you to determine how fast they are travelling. But it also enabled faster absorption, because the "constant" enabled study of the subtle mechanics of meditative absorption.
Anyway, for me, this constant was the tactile "tingling" charism. These days, I'm finding it most advantageous to marry the charisms which you already have the most development or affinity. Marrying them induces factors of enlightenment like Energy--which "unlocks" deeper attainment. I feel this is probably a lesser form of how Jhananda keeps all the senses in one field of consciousness. And for me to consider that is absolutely mind-blowing.
From what I feel, these charisms seem to have this... unifying quality. Like the tingling (fuzziness), the "visual' tingling (the noise-patterns of the light-streaks), the "auditory" tingling (in form of whistling), sometimes even a rich aroma (also giving off that tingling kind of nature). I kind of understand that they seem to come from a single field that has this vibrating quality, I'm not sure how to express it... So that's the reason why I keep switching around. Maybe it's a misconception, so I wish to clarify here.[/b]
UnificationAs you can see in the above answers, and in other posts in which I have perhaps discussed it too extensively--yes, there is a unifying quality to the charisms. I call it "connecting the dots." In my personal experience, the charisms come together the higher into the form and formless levels you go. It's difficult for me to explain this, because they also begin connecting and synergizing at lower levels--such as "reading" aura, leading to stream of insight, and energy, which synergizes and takes you deeper in that very moment.
This topic of "Unification" has been treated, however incompletely, in a separate thread in which I tried to put it into words.
I only list Faculties and abilities/charisms which I've had enough direct personal experience with. I've left out many extraordinary abilities that I just don't know enough about. To make matters more difficult; as the Faculties develop and the individual reaches Samadhi 6-8, the Faculties merge together. Because this could be very confusing, for most Faculties, the development line will end simply with "OOB."
If this triggers insight for you, then you can visit the rest of the topic here:
Jhanon's List of Supernatural AbilitiesI suppose I would now say the qualities and charisms in the form levels of samadhi 1-4 begin to synergize with each other the more you learn to utilize them, which gives birth to more knowledge.
In the upper formless samadhi, it certainly seems they come together into "omni-omni", which for lack of a better term means "All is one." But I have only a handful of experiences with samadhi 6-8, unlike Jhananda. Even so, it certainly feels accurate.