Hello!
I believe he completed a lecture tour because he need money so he could be rich.
I hope this helped you out! :)
I would say that what's common to Discretion, Strength, Five Wits, and Beauty is that they all forsaken him on his final journey.
God sends Death to Everyman to help him finish his journey, which is the moment when his so-called friends abandon him. It is a metaphor of life, that people will lose much of their senses when approached by death.
This idea is known as Uniformitarianism. It is based on the opinion that the natural laws have always been the same on Earth, thus the same geological processes have been occurring on Earth forever.