Agreed. I've always seen the proclamation in Luke 9 (the rock) as simply referring to faith in Christ, not one man (Peter).
Incidentally, I looked 1 Tim 3:15 up in the Interlinear which shows the verse in the Greek and there also my interpretation was confirmed...that the the living God is the foundation of truth.
Ephesians 2: 18-20 clearly states the believers are members of the household of the God. 1 Tim 3:15 clearly says that God's household is the church. This seems to support the view of the visible church (as in the building) and the invisible church (all believers). So whenever you read a verse talking about the church, there is no justification for proclaiming it is talking about the RCC.