Hey Cam,
Unlike Pilgrim, I'm neither too old nor too well versed in this subject.

So I enjoy talking about it, especially to others who hold different positions then I do.

Your original question about SolaFide and the Catholic Church's doctrine of Baptism is a really great question.
How is it that the Early Church who might have held dearly to faith in Christ alone; made the sacraments of the Church necessary and essential?
Again, I do believe that the Early Church were all over the place, but it's still a good question for us in the present age.
I was involved in a discussion about this very topic in a Lutheran Church Missouri Synod a few months ago.
All of the conservative Lutherans there held to their belief's on baptismal regeneration. With the conservative Lutherans, they do believe in "both" sacraments as being a "salvific" means of grace. i.e., all those who continue to participate in the Church's sacraments are receiving justifying grace.
This is also the position of the Catholic Church of course.... how is one assured of their salvation? If one stays near to the Church.
I for one have to reject this completely though as I see this as works righteousness.
For my personally, there is absolutely no justifying or saving grace in the receiving of the elements and or the dunking or sprinkling of the water in a physical way. I say physical meaning that it isn't "if I do this, I will be saved"
Now I'm not saying that these can't be a means of grace spiritually, God certainly does use these, but not in a guaranteed, if you do this you will be saved way. But in a God's Spirit works through these means when and where He will, but only when and where He will in a completely monorgistic, sovereign way.
Does that make sense?
Anyway.... I'm not a Theologian by any means, I'm just a simple layman. Most of what I say comes from my own understanding of Scripture and not from the writings of the great Reformers.
But for me; first off, one of the things that I like to point out to myself in our Church age is that most Protestant Church's are not operating the way I believe they should be.
I for one believe that the Protestant Church in many ways "should" be more like the Catholic Church was a hundred or so years back.
In other words, it's pretty clear to me through Scripture and through the early Church Fathers, especially like Ignatius of Antioch that the Visible Church should be the Lords visible Church here on earth.
I'm not sure how the WCF would state this, I'm just sharing here.
But in other words, "believers" or Christian disciples or anyone who like the Ethiopian Eunuch or the Jailor who desires to "be saved" should desire to enter into the visible Church and it should be the visible Church where one who truly desires to "stay in covenant and in grace" with God want to remain.
So, if the Visible Church admonishes someone, they will have to seriously consider their reaction of either disobedience and possible excommunication from the visible Church or their acceptance and repentance to therein remain in the visible Church.
Anyway, I say all of that to say that if our modern Protestant Church did operate in this way, and maybe some reformed churches still do, I don't know, there is none in my area that do; then the Sacraments would be, in my opinion, be much more easily seen and accepted as covenant actions.
Anyway, that's kind of how I see it.
What frustrates me is that I had a chance to move my family into a reformed church and I did but there was no discipline. I being the head of "my household" should have been supported by the Church in the teaching, instructing and admonition of the "rest" of my family, but that didn't happen. So eventually, in order to keep peace within my family, I had to leave that "reformed church" because they didn't do anything and when I told them I was planning on leaving they just smiled, waved and said ok dokey, good luck and if you change your mind your more then welcome to come back! Of course there were many in that church who didn't even believe in the infallibility of the Word of God, yet they professed to be a reformed church.
The point I guess I'm trying to make here is that I personally believe that while the sacraments are not a physical means of justifying grace in a physical way, I do believe that are absolutely necessary for our sanctification.
Dave