About the DNA found in JonBenet's underwear mixed with drops of her blood:
Melissa Weber, molecular biologist at CellMark Laboratories stated after CellMark analyzed the DNA in the Ramsey case that the so-called "foreign" DNA could be the result of a false positive (stutter.) She also stated that IF the "foreign" DNA wasn't stutter and that it came from more than one person, then NO ONE could be excluded, and that includes the Ramseys.
Despite what Weber said, Lou Smit and other Ramsey supporters, including Boulder DA Mary Lacy, insist that the "foreign" DNA doesn't match samples taken from Burke or John Ramsey. In fact, this is true only if the "foreign" DNA (if it really exists) came from just one person. It has never been determined whether the "foreign" DNA was real or stutter, or, in the event that it was real, how many individuals' DNA contributed to the sample. The sample, which was taken from the crotch of the underpants found on JonBenet's body, may even be spittle from a factory worker in Thailand who sneezed on the underpants during their manufacture. The name of this "suspect" is Sum Yung Gai. ;)
From the CBI (Colorado Bureau of Investigation) report on the DNA: (The blurry word is "Excluded."
As you can see from the CBI report excerpt above, if the "foreign" DNA sample came from more than one person, none of those named in the report can be excluded as possible donors.
That includes Burke Ramsey. (For that matter, neither can John Karr be excluded. Karr was cleared as a suspect because there was no evidence whatsoever that he was connected to the death of JonBenet.)
You make a good point about the incredibility of Burke sleeping through it when Patsy "found" the note and yelled for John. Also, on the unredacted tape of Patsy's 911 call, at the very end, a small voice is audible, and then John is heard to shout in a gruff voice, "We're not speaking to you!" Who was John addressing? The intruder? Hardly. He was speaking to Burke, of course. The small voice is thought by some analysts to say "What did you find?" and "What do I do?" I don't believe Burke was involved in the staging, so he was probably wondering what note his mom was telling the 911 operator she found. And then Burke wondered what he should do, how he should act, when the cops arrived. He was probably ordered back to bed and told to say he slept through everything.
BDIers are even considered pariah at most, if not all, "Ramsey did it" forums, and none of us discuss the BDI theory there. I have no idea how many of us there really are. I'm the only one I know of nowadays. Most posters on forums that are oriented toward Ramsey guilt believe Patsy killed JonBenet (there are lots of different PDI theories), though some think John did.
Every aspect of JonBenet's death points to Burke, in my opinion. Even though Lawrence Schiller treats him sympathetically in
Perfect Murder, Perfect Town, the evidence is there for those who dare to look.