How can we make better digital copy of our original paintings to improve sales?

What kind of the camera, lens, equipment or environment can help an artist make a perfect copy of an original painting to improve sales, if one does not have a professional studio???

I have taken photos of my paintings for years, but never can find a way to take a perfect copy of it. And I have noticed that I am not the only one here, so please share your knowledge, tricks or tips if you can help us to improve our captures, thank you!!

1) How to avoid the reflection if taking photos for your painting in the sun, especially for the oil painting with glossy vanish retouch? I even tried to used the Anti-reflection lens to help reduce the reflection, but it adding more blue color to each image.

2) How to show texture but avoid shadow overemphasizing the texture. Canvases have textures that look like pixels in the light (because the sunlit can never be 90 degree on the earth). I don't paint oils in a traditional way, some of my canvases are not 100% covered by paint after I finish painting. And the shadows of the paint are showing after taking photos in the light, etc.

3) How to avoid the fish eye shape? Most of the lens has the angle, so, the result can be different than the original painting. I try to avoid to take photos too close to the original paintings.

4) How to avoid the color change? I have tried to take photos for my painting outdoors, indoors, in the shade, etc.. and notices that the colors of photo can never be perfectly match the original paintings. And also, I tried to use different cameras in the same light and the same environment, the color result can be different too.