RSBM
Some of the items I have no knowledge or comments to make but can address the following with my opinions:
1 This hasn't been firmly established. We do not know time of death or even whether they were kidnapped by vehicle from under the bridge immediately and brought back later.
2. These three witnesses should be looked at extremely closely as being the closest in time to the 02.07 and 0230 events AFAWK
3. I have already mentioned the possibility of a boat. But nobody has thought that an option. I don't know why. After all, they brought a dive boat ( don't think it was needed in the end) to the crime scene so the creek must be thought to be navigable.
5. Was the crime scene clean? Could this mean the girls were taken elsewhere, then returned ? Otherwise, I do not know why they weren't found sooner. Number 1 is also relevant here and LE will know the answer to this.
Your points are very well thought out. Sorry I have no valid input on the rest and I think you have the scanner response already.
AJMO