Flaws in harry Potter.

1 I think Dumbledore entrusted it solely to Harry. He doesn't want Voldemort to know that they have learned about his secret, otherwise it would be hard for Harry to find them for Voldemort will really protect it and hide it well. Right? 3 It's a dark spell that only few people know. Remember how Tom Riddle had to asked Professor Slughorn and told him that he can't find it in some books about it in the library. Voldemort made it as his own secret and he thought that nobody would know about.

My response to your questions: 1) Dumbledore wasn't sure if Voldemort knew how to cast or create a horcrux successfully. He needed to be certain that Voldemort could do it. Its why he wanted the real unblurred memory of Slughorn to know the extent of Voldemort's capabilities. Yes, he got cursed by wearing the Gaunt's ring but he still wasn't certain if Voldemort really made the ring to be a horcrux. Or if Voldemort intentionally made it to be a horcrux. 2) Voldemort can't get past Snape's mind because Snape was at par with his mind abilities with Voldemort. Snape was always so devoid of feelings that Voldemort thought he could really trust Snape. And it was Snape who told him of the prophecy about Harry. That's got to count something for Voldemort. 3) This horcrux process was never expound in the book, but theory is, you have to kill a person and maybe do a chant (could be verbally or not) and you will able to break a piece of your soul to latch in to the next nearest object or in case of Harry, person. 4) Now that is the question I am wanting Dumbledore to answer. Along with why hadn't he dueled and defeated Voldemort years ago when the war was just beginning. 5) I think or my theory is the Deathly Hallows tri-magic can only work for the Peverell bloodline. Voldemort and Harry Potter can use them for their advantage since they have the Peverell blood. What's so fascinating with the Hallows was there were wizards wanting ultimate power and thought having the three items together could bring them that power. And Harry got the elder wand because he was its rightful owner as per the rules to wizard's duel. He pawned Draco who became the wand's master when he disarmed Dumbledore before he was killed which clearly Voldemort didn't know about.