You cherry picked Ephesians 2 for your catholic perspective. Let's keep the verse in context for a clear understanding of what Paul is saying.
I've included the verses just before and after to keep things in context.
Ephesians 2:4-10
But God, being rich in mercy, because of His great love with which He loved us,
5even when we were dead in our transgressions, made us alive together with Christ (by grace you have been saved),
6and raised us up with Him, and seated us with Him in the heavenly places in Christ Jesus,
7so that in the ages to come He might show the surpassing riches of His grace in kindness toward us in Christ Jesus.
8For by grace you have been saved through faith; and that not of yourselves, it is the gift of God;
9not as a result of works, so that no one may boast.
10For we are His workmanship, created in Christ Jesus for good works, which God prepared beforehand so that we would walk in them.
Regarding James 2 you need to go back and re-read and keep it in context. You also need to review the account in Genesis with Abraham to have a clear perspective of what happened first....his faith leading to being declared righteous or his "works" that came about afterwards.
Context of a passage is key.
Your method seem to be to explain "by faith," andexplain away everything else.
This method --- "explaining away" ---is not a careful use of context.
The bottom line is that we are to be conformed to Christ, incorporated into Christ. Every item on that list of 14 Biblical points, and all of them together, point to that. Here's Paul's description of it: "I live; yet not 'I', but Christ lives in me."
If that's really what you mean by "a living faith," then we're on the same page. If, on the other hand, you mean just some kind of intellectual notional, possibly coupled with a verbal formula, you're going to have to fully deal with James' teaching that there's a difference between a "living" faith and a "dead" faith, and you can't be saved by a dead faith.
Nor can you play Paul against James on this one. Paul himself says, "if I have all faith, so as to remove mountains, but have not love, I am nothing." (1 Cor.13:2)