I’ve probably taken a million miles of core photos with macro lenses in my lifetime. Zooming in and using the macro focus works fine. You get the same frame filling picture, but you don’t have to be as close. It makes lighting easier if your not right on top of the subject with the camera. The disadvantage is it narrows your depth of focus. A macro lens has a very narrow depth of focus anyway, maybe 5 cm or so if your lucky. Thus you have to move the camera in and out to get the subject in range. If you use a 2X zoom, the problem gets worse because it cuts depth of focus in half.
However, if you have a tripod and camera with manual settings and a timed or remote shutter release, you can overcome the problems. Go with a high numeric F-stop and a slower shutter speed. This will increase the depth of field. No need to use maximum F-stop, even the best lenses begin to distort at their max. or min. settings. If the shutter speed falls below 1/15, get more light.
Also, while your on the manual settings, set the ISO/ASA speed to something reasonable, like 400. Modern digital cameras claim light sensitivity beyond the fastest film ever invented. In practice, you get a lot of noise and poor resolution.
Lastly, looking at your most recent photo, the only thing I can suggest is check the white balance setting on your camera. It looks like its set for daylight while the subject is in tungsten light.
Hope this helps.