But we are saved (become that spiritually "risen" "new man") upon receiving Christ. Originally, this was intimately connected with water baptism, as in NT evangelism as soon as one accepted Christ, they were baptized on the spot. That was the "symbol" of "dying" with him, and "rising again". Now, of course, nobody just baptizes anyone right away, but instead gives them membership classes, etc. first. As I discuss on Altar Calls, Baptism, and Conversion, the altar call has become sort of what baptism was. This may not have been a scriptural change, but even the RCC does not follow the original practice in this. So you cannot say that Baptism is what saves or marks the death of the old man, and rise of the new. It was a symbol, that did basically mark that event, but is now separated from initial conversion.
Also, Christ did not "die" and "rise" in baptism; He died and rose in His actual death and resurrection. He was baptized to set the practice for us ("to fulfill all righteousness"), but only to us, is it a commemoration of His death and resurrection.
The act of coming together as a BODY —Christ's body, is what makes it sharing in the body and blood of Christ. Not some doctrine that bread and wine actually BECOMES literally and physically, the body and blood.
Notice in one place you say there are no "outward signs", but then you acknowledge that that is what they are. That is all I am saying. "Outward signs of spiritual realities!
No, that is not "two baptisms". You seem to be assuming that our view of repentance being what marks salvation corresponds to John's baptism "of repentance". But no, we believe like you that now it is different in that we are now given the Holy Spirit as you said. John's baptism was but a forerunner, and the two "baptisms" are in effect joined into one.
Regarding how "baptism doth now save" (1 Pet.3:21); it's baptism "by one spirit into one body" (becoming a Christian or member of Christ's body)(1 Cor. 12:13) that saves, and water baptism was the outward symbol of the person's conscience being cleared when he receives forgiveness for his sins, which are symbolically "buried" in the water, and than the "new man" rises out of it, as in a resurrection. As I said, the physical act originally accompanied the spiritual act, but now are separated by Church initiation. So the physical water baptism is not a "second baptism", but rather a part of the one baptism, though it may be delayed in time.
Then nobody is finally saved, but we constantly convert to Christ ("receive" Him) over and over again, but it is never enough. This too becomes strictly a works-salvation. Who can be saved, then? This is one reason RC's have no assurance, and say it is "presumptuous" to think one is saved. But what kind of "gospel" (good news) of "grace" is that? We might as well still be under the Law. Only difference is, we have jettisoned many Hebrew practices for gentile ones.