Just because they were intoxicated doesn't mean they shouldn't be able to tell us where they were. I have never been drunk enough in my entire life to not remember what house I slept at. Have you?

Intoxicated people as a rule have fuzzy and missing memories. I've definitely forgotten events when I've been drunk and I've had friends lose a couple hours of memory and wake up not knowing where they are. Maybe this isn't sufficient to explain the inconsistencies but it is once you combine it with scary, potentially abusive police yelling at and threatening them... well, I'd say some inaccurate testimony is to be expected.

That said I'm having trouble with their story of the morning the body was discovered.

So because the police were idiots and didn't record the interrogations that means they faked the evidence? What would be the police's motivation for faking the evidence?

Initially the police said they had lost the recording and later said they had never made one. In fact, they didn't even have a transcript of the the interrogation just a signed statement in flawless italian. These things "get lost" when the police realize the confession was coerced and won't hold up on appeal once people see the video tape. And are you really asking me why police would manufacture evidence to get a conviction? Like, are you kidding? If you want a motive unique to this case you might read the criticism of the Italian prosecutor. From the wikipedia page:

Mignini is currently under investigation for pursuit of bizarre and lurid psycho-sexual homicide theories in another Italian murder investigation, regarding a serial killer dubbed "The Monster of Florence." Criticism of Mignini's methods, accusations of mental instability and fascination with the occult have dogged him in the media and a senior Florentine minister has gone on the record stating his opinion that Mr Mignini had fallen "prey to a sort of delirium".

Evidence is held back for lots of reasons, doesn't didn't happen. It was on the wikipedia page so I'm taking it as fact.

It doesn't mean it didn't happen. It may have, I'm not convinced of their innocence. But the fact that it is on a contested wikipedia article is a terrible reason to take it as fact. Wikipedia is great for reading about the history of cheddar cheese, less so for answering questions about current, controversial and biasing events. Btw, did you really read the defense's site? Quoting:

Early in the trial, the prosecutor seemed to be aware that the washing machine was a matter of interest to people discussing the case on the Internet, because he made a point of asking several witnesses about it. But nothing of value emerged from these questions. Insiders have known for a long time that the police examined the contents of the washing machine and found nothing incriminating.

Finally:

However I can't invision reasonable argument against DNA evidence, unless there's evidence of a massive police conspiracy.

This was in the main section of the defense's site. Section 2.