What if Voldemort drew the Sword out of the stone? What if that meant Harry had to race against time to retrieve the Deathstick, the Resurrection Stone and the ultimate Cloak of Invisibility? What if he had had one of those items all along?
No, this doesn't exist AFAIK - I just now invented this 'summary' to showcase the idiocy of multiple what-ifs in summaries.
To be honest, that's the best written multi-what if summary that I've ever seen. The second what-if is put in place due to the first and the last isn't that bad, just extra. Honestly I wouldn't call that a bad summary, though it deos overuse the term "what if" just a bit.
One that I would consider a bad summary, plus a bad story, would be disjointed and have no ties to the earliest point of alteration to the timeline that a what-if would normally effect.
My Example:
What if Harry was the destined wielder of the Robe of Ultra-Magic? What if Voldemort had a Nundu as a pet? What if Ron was Merlin's reincarnation?
To me the above is an abomination of a summary that has no logical ties to what the first what-if would be.
Though I would say that this is my problems with most What-If's that I find out there. We have one pretty cool idea that on it's own could change the majority of the story in a new and interesting way but the author wants to add unnecessary plot twists just to add 'drama' or so I gather from reading.
Though these are my thoughts and they might not align with yours, which is cool. Please let me know what you think!