Why become a RC if a protestant can receive god's grace regardless of their fully-informed rejection of the RCC?
I believe the reason is that fully-informed rejection of Christ's Church is a pretty big deal. That is, why would a fully-informed Christian reject the Church Christ built, and could he call himself a Christian if he did so?
But lots of people have too much pride to allow themselves to become fully-informed. On the other hand, it is not only Protestants who have this problem, so Christ will have to make a judgment call, I guess.
So somebody who dies in active opposition to the RCC is not in any danger of eternal torment in hell then?
Wouldn't say that. More like: everybody is in danger of making a final choice against God. I think you are still working with JW-style IF THEN statements.