To me why he is called Ben in ANH probably didnt need any explaining, nor did why Luke kept his Skywalker name, i take it he never gave his surname out, or it was probably popular name though the reasons may appear in EU or some spinoff.
Its all the issues that have been brought up, some of which i would have problems with. Why didnt Lucas cover these all throughly,which could be done without him needing to dumb it down, instead of leaving it up to peoples intereptation and having people explain for him, and what they think the answers are...