So those are just a few warm up items...
Who is going to pay for this? Bonds just like they do for upgrades and new schools now.
How quickly could these schools be retro fit or built? Depends on what needs to be done, but the simplest ones can be done over the summer.
Will private schools be required to make these changes? No.
How in the hell are you going to secure a football game, prom, or sporting event? Hire more police to moonlight and metal detectors at the gates.
Does anyone really think our kids should be raised like this? Yes, the safer I can make them, the better.
Where is the marginal sweet spot and how do you defend it after the next school shooting.... this seems very slippery slope. No idea.
These are a few things that I would be in favor of that would be easy to implement:
Metal detectors/bag inspection at designated entrances. Some schools only need one, some will need more. All other doors to the school are fire exits.
Student Ids scanned when the student enters the school, and scanned when they leave. If a student is scanned in, and they are not in class or accounted for (office, nurse, lunch), security will be notified to locate the student.
Distinguishable active shooter alarm that is different than the fire alarm. We don't want students walking out of the classroom.
All classroom doors closed during class and locked from the outside when the door is closed. Can be opened from the inside or with a key.
Clear backpacks.