As for your second point, there's been testimony in one of these trials that people don't drown when they fall asleep. They'd start choking and wake up
On your third point, you're really grasping at anything.
Your reponses all add up to one thing: It'd be off the chart rare for her to just die. So rare you can't even come up with a scenario.
I think the reason a lot of the public would vote for non guilty and 34 out of 36 jurors have voted guilty has to do with the judge's instructions on reasonable doubt. Most observers not on the jury didn't hear or take to heart those instructions. Some of you here want him guilty beyond a shadow of a doubt.
Do a little Googling on reasonable doubt. This study put it at about 70%:
In other words if you're 70% sure he's guilty then you believe he's guilty beyond a reasonable doubt.
Of all the possible scenarios, do you really think there's about a 30% chance that she just mysteriously drowned without him laying a hand on her?
My guess is the chances of a healthy 24 yr old drowning at home, not due to a heart or stroke issue is about one in a million