In the beginning of the film, how did that many soldiers sneak into Don Diego's house? I know he was distracted by his wife and child, but there were a lot of soldiers, with heavy boots, and he's freaking Zorro. Yet they've made their way up the stairs and into the house without him noticing. What gives?
He was tired and sleepy, and they may have been trying to come in quietly. It's not a huge difference, but it might just have been enough.
Yeah, they most likely just walked in at a nice slow pace, which while it would still have been noisy, would not have been nearly as much so had they been running or marching. Besides, it's a big house.
About the arrest scene: how did Montero deduce that Don Diego was Zorro? Yes, he found Don Diego's arm wound, but he clearly knew the truth before that. Also, in the opening scene, Montero's friend tells him that Santa Anna's troops are an hour away, and that Montero imperatively needs to leave town before they arrive. But Don Diego's arrest-at least the part where he's carted away in a prison wagon-seems to take place at least two hours later. So why is Montero still here?
From the scene, it's implied that Montero at least suspected Don Diego for some time, but for various reasons couldn't act on it. (What if he was wrong? Falsely accusing another nobleman would be a big deal.) The scene at the house where he found Diego's wound confirmed it for him. And since Montero was being ousted anyway, he could take the chance. Also by the time Santa Anna got to the capital, Montero had left, so there was no reason to go after him. Montero had this one chance just before he had to leave Mexico to finally defeat his rival, so he took it.
It's not that Montero has suspected him all along, it's that he figured it out during that day's events. de la Vega always pronounced his name in a specific manner, and when Zorro called him by name with the same pronunciation during the attempted public execution Montero was shown tilting his head with a recognizing expression. So, that's when he thought "Wait...Diego?" and went to his house to confirm and capture him.
Your explanation would make sense, but that's not the way things are presented in the movie. We're never made to believe that de la Vega pronounced Montero's name in a distinctive manner. Montero does give Zorro a recognising expression during their encounter, but that could very well be because Zorro used his first name (implying that he knew him well).
That latter bit is unlikely, since Diego calls him "Don Rafael" and acts deferential, while only Zorro calls him Rafael- in other words, Zorro is on more personal terms with him (likely just due to being his Arch-Enemy) than de la Vega is (sounds like these two had an incredible backstory in fact, probably a whole series could have been made of their enmity).
So the one soldier guy starts as an outpost commander, gets made a fool of. We later see him in charge of a garrison, where we see him get made a fool of. Then we see him guarding Montero's house, seemingly in a command position. That's pretty good job security.
If he were somehow connected to the local nobility, that would easily have been enough.
He probably makes sure that word of him being made a fool of doesn't get out (which shouldn't be hard, since his men would be the only ones anybody would listen to, and THEY were made fools of themselves). Besides, it is possible that he was ALWAYS a garrison commander and was only in that outpost on business or some other capacity, and him being in charge of Monteros security is probably more to do with the fact that Montero returned and now NEEDS security so he takes it from the local garrison- prior to this, the house may well have been empty, so there were no guards around to begin with.
Before Alejandro introduces himself and ingratiates himself with Don Raphael, his "servant" hands some paper to a guard allowing him access to Raphael. Shouldn't that have been a problem that this stranger from Spain could get that far in the first place?
Raphael probably had security to deal with most potential intruders from the lower classes, and considering his elitist attitude he wouldn't believe that anyone on his social level would be a threat.
Note the reason that Alejandro gives to be in the area: "I am inspecting my family's holdings." This banquet's invitations had been sent out to a great many people, so it's not unbelievable that the son of a Don would take up the invitation letter from an underling and use it to ingratiate himself with the local nobility. The doorman is only checking that they have an invitation, one that Diego de la Vega could easily forge, not to whom it is addressed.
How exactly did de la Vega get wounded? He's duelling three mooks at once on top of the gallows without a scratch, hits the lever to open the trapdoor, and suddenly he's got a gash on his arm. Was there something cut from the film?
Based on the timing, I assumed that he got cut on a damaged board of some sort when he fell through the trapdoor; considering that the shooting was set up on relative impulse by Raphael, shoddy construction-work isn't that much of a stretch.
How is Captain Harrison Love able to drink from wine jars containing body parts without getting intoxicated or severely sick? That water should obviously be contaminated due to the putrid state of the corpses. Even if Joaquín's corpse was healthy, Three-Finger Jack's corpse definitely wasn't...
While fighting against Zorro on El Dorado, after knocking him into an ingot elevator, Captain Love strikes one of the elevator's ropes with his sword. If he did this, shouldn't the ropes have snapped slowly and sent both Love and Zorro to their deaths below?
The ropes were fairly thick and the swords are relatively thin; I don't think they'd be strong enough to break the ropes as implied.
