Harry gives some of his life (what does this even mean? Vitalism?) and magic to resurrect Hermione. Suppose he's given x% of his magic. Does this mean that Hermione has x% of Harry's magic, now and forever? For that matter, are the sums of their lifespans equal to Harry's previous natural lifespan? Or does it work like a spark, a small amount allowing Hermione to bootstrap back to full health?

If the second option is right, then patronus 2.0 + philosophers stone allows almost self-replicating wizards and witches. The only bottleneck is the stone takes "minutes" to work which still seems to imply that you could easily produce hundreds of wizard clones per day, against a wizard population of about 15000 in muggle Britain. Clone someone powerful, and world domination should be easy.