1. It is pretty clear that at VT, the state system failed in identifying Cho and having him in the NICS system. Lochner was similarly troublesome. His school acted against him quite appropriately.
So what is the line for a NICS report?
I think one important issue raised by Virginia Tech shooting addresses the current split in law among the circuit courts. As it stands now, the 5th and 8th Circuit take the view that unless the state involuntarily committed you to a mental hospital under a hearing with due process you do not lose your 2nd Amendment rights.
The First Circuit takes the view that "adjudicated mentally ill" indicates Congress intended to cover a broader range of people than just those involuntarily committed and even a temporary detention for observation (similar to Florida's Baker Act) can permanently deprive you of your Second Amendment rights, even if the state law you were detained under specifically does not intend to remove your firearms rights.
The Cho case falls right into that gap. Cho did have an adversarial hearing where he was found to be a danger to himself or others. He was temporarily detained and then ordered into outpatient treatment. Under Virginia law, Cho would not have lost his firearms rights. Under federal law, he might have, depending on what circuit court heard the case.
I think the case shows a real problem - in that I don't really have a problem with people with a long history of mental illness who are found to be a danger to themselves or others in an adversarial court hearing being denied the right to bear arms. However, I do have a real problem with non-judicial, non-adversarial hearings resulting in only temporary detentions being used to have the same effect.
2. If we have tougher reporting, what is the level of false positives that we will accept - with appropriate appeal mechanisms?
A big issue now is that there is no appeal from being a prohibited person. Once you are on that list, you are there practically forever as Congress has not chosen to fund the appeals process.
The NICS Improvement Act created an appeals process for mental illness prohibitions that would be administered by the states; but so far the states have declined to set up that process. Since they also don't get any additional federal funds to improve their NICS records if they don't do this, it is pretty much the same situation that existed before the Act.
3. Is a tougher systems really a slippery slope so that the camel can slide into the tent? Certainly, gun rights are on the ascension.
It hasn't been that long ago that was not the case though. One of the great things about TFL is you can read some of the debates from the Columbine-era where it looked like we were going to get yet another piece of bad legislation on top of the Brady Act, Lautenberg Amendment and AWB. I'm a lot more politically savvy than I was then; but I think the concern over slippery slopes is a very realistic one - especially given some of the past statements by people on the other side of this debate.