Corrected entry: The T-Virus escapes through the air vent and spreads throughout the entire building, so the air vents must go all over. Later water floods the labs, all of which have air vents, so the rooms shouldn't have filled with water, it should have poured through the air vents and spread throughout the building.
Corrected entry: The T-Virus is being developed as a biological weapon. The virus doesn't kick into effect unless someone is wounded or dead, and even then it resurrects them as the "living dead". Those that are living and are exposed to the virus without treatment are perfectly fine for a good length of time before mutation into the "Nemesis", allowing ample time for retaliation. Not the best weapon around.
Correction: As you can see from the chaos inside the Hive and in Racoon City after the breach, if the T-Virus were used on a large group of people with no anti-virus provided a large number of them would be turned into zombies. Since even a little scratch from one is enough to turn you into a zombie, pretty soon a whole city could be infected. Seems like a pretty good weapon to me.
Corrected entry: In the scene by the elevator at the start where the woman gets stuck in the lift doors and gets decapitated you clearly can see the skyline of the city filled with other skyscrapers and it is broad daylight outside the window, yet the Hive is located underground.
Correction: When the team first enter that part Matt says something about how since they have a view it makes it easier to work underground. my guess it's computer generated.
Correction: The red queen could have sealed of the ventilation system in that room when it detected the broken virus sample.
Hamax