Oh KC, where to start with your lunacy....
Considering handguns account for >95% of "mass shootings" that take place, your ban on "assault" weapons would be worthless. Besides, the "assault" ban only targeted scary looking rifles. A bolt action .308 will cause a lot more damage than an AR-15, and at a farther range... A traditional stock .223 rifle without the scary telescoping stock or the rail for mounting accessories was completely legal under the Clinton era ban, and is functionally the same as those scary looking "AR-47"'s that the media likes to claim stands for "Assault Rifle 47"....
Magazine limits?... The reality is that magazines holding more than 10 are likely to jam, so that's probably one of the biggest "meh" changes that's proposed. Sounds effective, but wouldn't really affect anything.
The Las Vegas shooter was firing for almost 10 minutes. Parkland shooter was firing for five minutes. Those of us who shoot regularly can swap out a magazine quickly enough that reloading would only pause a shooter for 3-5 seconds. Maybe 10 seconds if they're not experienced. That's not going to be a meaningful enough time for law enforcement to be able to respond. But hey, it's "doing something!"
Background checks? Already happens. Every "mass shooter" that the media covers (they ignore the gang bangers who do >98% of the killing) has passed a background check. If you haven't done anything wrong, you pass. Most of these media-hyped killers haven't ever been violent until they start killing people...
Red flag laws? Already exist in CO, FL, IN, NV, and CA, which are where some of the more publicized incidents have taken place. Again, they only work if the person is displaying signs of instability and it gets noticed and reported. If people don't report instability (which is most often the case), those laws can't work.
Require military service? That has to be the most ignorant reading of the Second Amendment I've seen. Active and inactive/national guard account for about 1% of the population. Including veterans, you might get up to 8%. So your "plan" would completely disarm anyone 92% of the country?...
The Second Amendment doesn't protect the right to form a militia. It protects the private right of individuals to have arms for their own defense, be it from a tyrannical government or criminals.
You're free to call the police when seconds matter. I won't need to.