When I said there’s no division within the Catholic Church, I didn’t mean there aren’t any wolves or wrongdoers, I meant that the faith is intact. We hold to the same beliefs and doctrines. There will always be elements of sinful man in all walks of life.
Regarding the visible Church, I believe it does mean that, specifically verses 14 and 15. I’m sure there are other meanings, too. There are invisible aspects of the Church, also, such as prayer, almsgiving etc. so I don’t mean to discount all other good works that aren’t seen.
Edit: something just occurred to me, I wasn’t speaking of the buildings themselves, but the body of Christ, the believers holding to the same faith. The buildings are nice, of course, but not essential to the visible Church.
Edit 2: I feel obliged to clarify some points:
I believe that all the baptised from other Christian faiths are grafted into the Church, the Body of Christ. I believe that the Church should be visible to all peoples on Earth as a light to the World, and I believe that the Catholic Church has held firmly to the faith, and that other Christians have grown up in faith groups that have previously altered aspects of the faith many years ago, in some cases beyond recognition …I believe this is through no fault of these modern Christians and that very many are seeking God in sincerity, so I’m not looking to criticise you or anyone else. I believe that salvation is available to all people that do God’s will - love God and love neighbour. The best way to see where the real truth is is to start at the very beginning of Christianity to see exactly what’s gone on before. See how Christianity progressed.
Edit 4

We are meant to be like little children - docile and trusting. Being Catholic would make salvation much easier as we have other Sacraments to help us (including forgiveness of serious sins) which give us the grace we need to walk this path. The other point I was thinking is that we all have to be willing to follow where God leads us. One would have to be willing to do God’s will rather than following our own will …so that may eventually mean your conversion

All I’m really suggesting is to be open hearted.