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Victories of the Martyrs by Saint Alphonsus has several accounts of men, women, and children that are venerated as saints in the Latin and Oriental churches that did not receive baptism by water. I'm fairly sure that this book is free from theological and dogmatic error.

There's no proof whatsoever that the saint-martyrs cited didn't actually receive water baptism.  These accounts come from the martyrologies, and each one indicates that the person was a catechumen when they committed whatever acts eventually led to their martyrdom, but does not rule out water baptism.  Now, there are references in the Church Fathers and other early Church docuмents using the word catechumen in reference to post-baptismal neophytes who had not yet been fully instructed in the faith--as would be the case of those who had received emergency water baptism due to impending martyrdom.  So someone who had not completed his formal course of instruction, even if water baptized in an emergency, would still be called a "catechumen".  In fact, we do have early Church legislation ordering catechumens to be baptized in danger of death but then mandating that their instruction continue afterwards if death does not come about.

No, the Blessed Virgin Mary was an exception, in the sense that She had the fruits of Our Lord's Passion applied to Her beforehand.  Read the Council of Trent's decree on justification, which clearly distinguishes between the subjective dispositions necessary for justification and the "justification itself" which comes AFTERWARDS as a result of the application of Our Lord's Passion by Baptism.

Anyone who was justified prior to the Passion had It's fruits applied antecedently.  Otherwise, you'd have to posit something other than grace as a means to justify a soul.  And making reference to the dispositions of to justification only beg the question, for if they were not justified, then they were not in a state of grace.  If they were not in a state of grace, they remained enemies of God.  

But to address the original point, it remains true that they were and are considered "martyrs" for Jesus Christ by the Church.  As such, it follows that there can be infant martyrs after His Passion as well.  It seems strange that I would have to say this.

Yes, they were martyrs, but their martyrdom wasn't the cause of their justification, i.e. they were not saved by BoB.  They were saved by being in a state of pre-justification per the old dispensation.  Even the Holy Innocents were hanging out in the Limbo of the Fathers until Our Lord's Passion was applied to them.  Why?  Because, DESPITE their martyrdom, they were not yet justified.  Otherwise, the Holy Innocents would have gone straight to heaven.  But they didn't.  Which proves my point.

To die for the Faith remits guilt and punishment for since and presupposes justice and divine charity.  BoB has been referred to as a quasi-sacramant precisely because of this effect.  In fact, theologians, following St. Thomas, exlain that baptism of blood is a more perfect form of baptism even than that of water because it so closely imitates the "baptism" of the Passion.

And this would raise other issues if they were saved by this martyrdom, because then you're saying that BoB works ex opere operato even in those who have not reached the age of reason, i.e. you'd be saying that BoB is in fact a Sacrament, which it is not.

It is a quasi-sacrament.  

So, no, Caminus, YOUR position is theologically erroneous.  To say that sanctifying grace somehow justifies (and can even exist) apart from the free-grace unmerited application of Christ's merits by Baptism contradicts the Council of Trent's decree on justification.  You're almost implying that people can earn justification by getting into a state of sanctification--which is PRECISELY why I reject BoB and BoD.

On the contrary, your position is erroneous and the more obstinately you adhere to your opinions, the greater danger you are of sinning.  A man can no more "earn" grace in the improper sense you imply in martyrdom than in baptism.  Either a man walks up to the font of baptism to "die with Christ" or a man walks up to the gallows to do the same.  The later is obviously more glorious, thus the reason St. Thomas gives for its sanctifying effects.

Anyone who was justified prior to the Passion had It's fruits applied antecedently.  Otherwise, you'd have to posit something other than grace as a means to justify a soul.

Then you explain why there was a Limbo of the Fathers in the first place, eh?  Those people in the Limbo of the Fathers had the antecedent dispositions necessary but not the "justification itself" which Trent defines as coming AFTER those dispositions which BoD advocates claim justify.

THAT is the very meaning and significance of the dogma that Christ descended into "hell" (i.e. the nether regions).  Those souls were suspended in a pre-justified state until Christ applied the fruits of His Passion to them.  They were not in a state of sanctifying grace or justification when they died.  You're confusing the new dispensation with how this worked for the "just" in the old dispensation.