The above statements are inconsistent with each other and with the gospel. If Salvation is by grace alone (which it is), then baptism is not a means to salvation. Otherwise grace is not alone but accompanied by works like baptism and "frequent reception of the sacraments".
As I pointed out earlier, Paul distinguished between baptism and the gospel that saves (1 Cor. 1, 15).
As I've stated correctly, Rome does not teach salvation by grace alone through faith alone. The Council of Trent is clear about this, and goes so far as to pronounce "anathema" to anyone who says that one is justified by grace alone through faith alone. But the Bible teaches that Justification is by grace alone through faith alone.
I guess what I'm trying to say is that grace is always primary in conversion. But that doesn't make Baptism unneccesary as a means of receiving grace. Baptism is the normative way of receiving sanctifying grace, God's life within us.
For example, the desire for conversion is prompted by grace, so the desire to receive Baptism is prompted by grace. (Catholics call this kind of grace 'actual grace.') The grace imparted in Baptism is different from actual grace. Baptism is the means for receiving initial sanctifying grace (or 'justification'). 'Sanctifying grace' is God's life within us. In Baptism, we receive the indwelling of the Holy Spirit. (Since we believe in the gratuitousness of salvific grace, infant Baptism doesn't represent a problem.)
For Catholics, the sacraments offer the normal means for receiving sanctifying grace, for increasing God's life within us.
The important difference between our views, I think, is that Catholics see God's life within us waxing and waning. We can say "no" to God's grace by sinning. The more we sin, the more we lose sanctifying grace or God's life within us. We can lose it altogether if we sin grievously. However, God always prompts us to return to him through 'actual grace.' For example, the desire to receive the sacrament of Reconciliaiton would be an actual grace. Then God's life will return to the penitent through the sacrament of Reconciliation.