Was Sailor Moon edited in the English version? Was Sailor Moon edited for the English version, to show less in the transformation when they are naked? Was it originally meant for children?
In general, Sailor Moon was heavily edited for the US release as detailed by fans for example here. In particular nudity was avoided as exemplified below.





The source of these images is this comparison between the US and the German version. While the German version is not completely uncensored (see the linked site for details) it is almost equal to the Japanese original and does not have censorship of nudity.

Regarding the transformation scenes in particular: Many sites claim the US censorship manifested itself in removal of the breast outlines, however all examples I find on youtube look the same to me. The two sites mentioned above also say that the only change is a speed-up of the transformation - likely to fit the overall episode runtime due to other edits.

Other changes include the removal of violence in particular against children and gender changes as not to display homosexuality. This all pertains to the original US release, while subsequent ones apparently stayed more true to the Japanese original.

To address the second question, as Skullclutter already mentioned Sailor Moon is considered a shōjo series and therefore aimed at young women.