First experience with the Celestron 102mm wide view spotting scope

My initial reaction after looking through it towards the grassy land (using the supplied 20x eyepiece) outside my home in India was quite good. However, after I used the supplied 50X eyepiece in the daylight and looked at the trees against a white background, blue tinge (Chromatic aberration) became apparent at the borders of tree leaves.
While viewing moon in the night (50X eyepiece), various craters on its surface can be seen easily. However, I noticed a lack of contrast on the moon's surface with a bit of blurred
view towards the moon's edges, while the central portion appear to be properly focussed. A look through the Objective lens along the telescope axis in the daytime revealed bright white reflection from one optical surface inside it. Objective and eyepiece lenses are coated. However, I found that the erecting prism is not coated at all, explaining the lack of contrast while viewing bright moon half way in its lunar cycle. I must mention that Celestron is misinforming the buyer by writing "Fully multi coated optics" in their web page about this scope. But in reality, the erecting prism is not coated at all. Following a report in the web, I suspected that the prism could be responsible for a lack of focus on objects further away from the field centre. The next day I removed the prism and joined my eyepiece (50X) to a barlow lens holder after removing its lenses to compensate for the optical path contributed by the prism, and put at the position of the prism. The view is then straight through the tube and I focussed the trees located a few hundred metres away. The trees looked upside down but I could see minute details of them across the whole field of view. I felt that the chromatic aberration also went down. After replacing the prism, I found that either I could focus sharply on objects near the field centre or on objects near the edges, but not both together. Therefore, I counclude that the prism is also optically imperfect.
I believe Celestron must upgrade the quality of their erecting prism, or otherwise add an warning on its problems and ways of using it (e.g., only with 20X eyepiece for terrestrial observations). I have noticed that the stars beyond the central 50% of the field of view also appear defocussed while observing with the 20X eyepiece in the night. Most of it I believe is due to a faulty erecting prism.