It's true that Apollo 10's lander was overweight. Late in the craft's development, it became clear that its ballooning weight was endangering the whole mission.
Sure, there were hopes that Constellation's systems could later be adapted to support more ambitious goals. But Apollo had those hopes, too. It didn't work in 1970, and it wasn't going to work in 2020.
The original specifications for Apollo navigation called for the ability to fly a complete mission, including a lunar landing, with no help from Earth - none, not even voice communications.
Speaking of photography, while the Apollo 8 crew shot hundreds of photos, there was one that got everybody's attention: a blue-and-white Earth rising over a gray moonscape.
Sometimes a malfunctioning test setup actually gives the tested system a chance to show what it can do in an unrehearsed emergency. During a test of an Apollo escape system in the 1960s, the escape system successfully got the capsule clear of a malfunctioning test rocket.