Won't go point by point, but I'd like to comment that while your conclusions are very intelligently stated and well sourced, I would add that you also include a number of speculations and assumptions that may or may not be true. For one thing - the elevator video. You see one thing, I see a scared girl. Why I believe she was scared is up for debate. Again, either a paranoid schizophrenia type of thing, or she legitimately was afraid of someone in the hall. That is entirely open to interpretation, and if it was the latter then of course some of us might be skeptical about "accidental". Secondly, her clothes and personal items being in the tank with her would actually be a smart thing to do by a perp as it would suggest suicide or accidental more than homicide of hiding a naked body in a tank. Additionally, the fact that her father said she was not bi-polar may or may not be true. It is possible that some of her medications were used off-label, and her comments on feeling bi-polar may be her own feelings on it, rather than a professional psychiatrist. Remember, the psychiatrist's diagnosis' has never been put on record. Ultimately what I'm saying is that "accidental death" may be a logical conclusion for law enforcement, but no matter how you cut it, it is still somewhat speculative as, wacked-out theories they may be, there are other ways for this to have happened beside accident or suicide. Maybe not likely, but they are still technically "possible". And despite your dismissal of her father's comments on her psychological issues, I would still point to further quotes from the article:
"The father of a Chinese-Canadian woman whose body was discovered in a hotel's rooftop water tank in downtown Los Angeles said he is unsatisfied with the autopsy conclusion that his daughter accidentally drowned, Canadian media reported.
Lam’s father said that he is planning a trip to L.A. to get more information himself, according to the report."
SNIP
"“How did she climb up (to the rooftop tower) and how did she die? These questions remain unclear,” said Lam’s father to the newspaper Sing Tao Daily. He also said his daughter was alert and quiet that she was not bipolar."