This does not imply that prophecies have intended recipients, though.

I'm not sure that's the way of it in the HPMOR universe. Consider the final chapter- who were those aborted prophecies for?

Why doesn't voldemort have a source of prophecies? If I were him, I'd have kidnapped a known seer, and kept them locked up inside a mountain, or something like that, and recorded their output like it seems dumbledore does. Every power he sees he tries to take for himself, etc..

There was something this summer, but I missed it.

The deeper problem in Ch. 6 is that Harry’s conflict with Professor McGonagall looks too much like a victory – it is a major flaw of Methods that Harry doesn’t lose hard until Ch. 10, so he must at least not win too much before then. That’s the part I’m working on at this very instant.

Strongly disagree with this. That's the bit that caused me to continue reading. Luckily, I have the raw text downloaded, and can make my own canonical printed version.

But Professor McGonagall had made other visits after her first trip, to "see how Miss Granger is doing"; and Roberta couldn't help but think that if Hermione said her parents were being troublesome about her witching career, something would be done to fix them...

This quote in particular makes that point...

I'm not sure the Powers that Be at Hogwarts would allow her to be taken home by her parents...

I think that Salazar's Serpent was a trap Tom Riddle fell into. It was a Langford Basilisk Horcrux, like the book Ginny got in the original timeline, so When Tom Riddle read out the information embedded, he was possessed by Salazar Slytherin. That's why nppbeqvat gb Ibyqrzbeg/Evqqyr/Fnynmne vg frrzf gb unir whfg orra n terng frecrag, abg n onfvyvfx, juvpu vf whfg jung ur jbhyq fnl. Guvf nyfb rkcynvaf gur qnzntrq guvaxvat Uneel frrf.

This might well explain Harry as well, since in OT Voldemort had a giant serpent hanging around. He might not have had one in this timeline, but if he did, it would explain a lot of why he kept it around- it was a horcrux duplicator/imprinter.

I admit all the above flaws.

In re: Interdict of Merlin- if the Interdict of Merlin did not block the creation of high-level spells, the loss of old high level spells would not matter, since newly invented high level spells would replace them. You might say that this is due to loss of knowledge, but then we have to assume that the interdict of Merlin actually limits not only spells but also knowledge.

In re: Random Effects: Booger-tasting jelly beans from OT universe would be one.