Suggest Remedies For Dark Skin Pigmentation

Question: What I (think that I) know:

I know that melanin is a skin pigment that determines how dark or XXXXXXX a person is, and that it's production is somewhat determined by genetics combined with UV exposure. From my understanding, things like freckles, age spots, melasma, and general uneven skin tone are all caused by an uneven distribution of melanin in the skin. It is also my understanding that treatments (such as hydroquinone) aimed at improving the evenness of skin tone - or even just overall lightness - often work by targeting melanin production and somehow inhibiting or reducing the amount of melanin produced by cells, whereas other treatments (like lasers and IPL and chemical peels) destroy or break apart or burn-off the melanin. I've even heard of a drug (Melanotan) that increases melanin production to make someone more XXXXXXX And finally, I've learned that melanin is produced by certain cells called melanocytes, and that treatments aimed at changing pigmentation often are targeting the action of these cells,

What I don't get:

Where my understanding falters, is in why melanin is produced more in one spot of skin than another, or more in one person than another, and how that is determined by melanocytes. Do people with darker skin have more melanocytes, or just produce more melanin with the ones they have? Why would a melanocyte two inches over from another, with the same amount of UV light exposed to it, produce a big blob of melanin (an age spot or freckle) whereas the other didn't? Or is the case that the melanocytes aren't evenly distributed themselves - in which case, why does that happen? And related to that, if melanocytes aren't distributed evenly, why don't skin care treatments target the cells themselves, instead of their action? Is it possible to target and destroy melanocytes like the procedures that destroy hair follicles for permanent hair removal? Or is there a way to grow or even transplant more melanocytes where they are lacking (like how hair follicles are moved to treat male-pattern baldness)? And if melanocytes are moved with a skin graft (like in a burn patient) - do those melanocytes act the same as they always did, or do they change based on new factors (like host genes)? Would skin donated by a XXXXXXX person stay XXXXXXX if transplanted to a less-tan person, or would it fade over time? for me skin uneven XXXXXXX is reducing only if i take whitening tabs otherwise application of creams on outside is not working. so is there any method which works directly on melanocytes to make them produce less and evenly like light skin people?

That's a lot of questions, I know - but need to know