do all of Yogananda's teachings hold up to modern science? where did he stand on the evolution vs creationism issue?
Your question really would require a book to answer it. There is a wonderful book that explores the answer to the part of your question on evolution vs creationism, and other aspects of modern thought: Out of the Labyrinth by Swami Kriyananda. (You will find this truly fascinating reading.)
The basic premise is that the idea of there being an intelligent force behind creation does not mean evolution is not also possible, acting as it does through the intelligence at the heart of each being in creation.
Today, modern physics is coming around to discovering things that have been described in the ancient yogic texts from thousands of years ago: the idea that matter is energy is something that has been well known to yogis. Some modern physicists are now beginning to suspect that matter is truly an expression of thought, another principle expressed in the ancient teachings of India.
Yoga, unlike religion, is not dependent on dogma. Rather it asks the practitioner to experiment on himself (just like a scientific experiment) and see what results he discovers from his own experience.
I encourage you to take up such experiments! — Yoga means not only yoga postures, but the whole science of redirecting energy inward and upward for Self-realization, especially meditation.
May your experimenting be blessed!