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The fuel pressure regulator update is a good idea, inexpensive and easy way to pick up fuel pressure if it's low. I don't think it the main problem however.
I'd check warranty info on that BPD FICM and have them check it or if it's out of warranty send it to ED at FICM.com (MANY satisfied customers here).
Given your description of how the codes pop up I suspect the FICM connectors are the culprit. It's possible there are some harness chaffing issues as well. Here's some info from the Tech folder on how to repair the connectors: