How should western practitioners approach the sutras? What are the most important sutras from the main Buddhist traditions for westerners to study? When studying the sutras should that be considered a form of meditation?
I practice with the Triratna Buddhists which is an explicit attempt to bring Buddhism into the Western context. It is ecumenical so brings in all traditions so for me this question is very interesting. For us the sutras that are particularly studied are
Pali Canon Middle Length Discourses generally but more specifically from the pali canon
This list isn't exhaustive by any means but I think represents the ones that are referenced most frequently. However a lot of others come up particularly from the Pali Canon such as the Gotami Sutta and even outside of Buddhism altogether such as the poetry of Rumi.
Since the question is broad my answer is opinionated towards the Theravada tradition.
Main aspect of Buddhism is that your practice should cover the 8 fold path (which is part of Bodhipakkhiyādhammā). Out of which a major part is meditation but ethics / morality is important.
Your choice of study ideally should cover the Bodhipakkhiyādhammā, Dependent Origination, and 4 Noble Truths. You should pick a set of Suttas covering these areas which suits your temperament.