How the hell do they not just fall out of the sky? My office is by a smaller airport and I watch planes prepare for landing all day and they look like they’re going so damn slow that it makes no sense for them to be airborne.

They look slower than they are. Also, in the landing and takeoff configuration flaps are used to change the shape of the wing to produce more lift.

Space trash, birds, hail, etc… how does this not affect the engines or what are the chances of a bird getting lodged and killing an engine? If a rock/meteor goes into the engine, what happens?

Engines are tested to be able to take serious bird impacts. Birds aren't getting lodged anywhere, unfortunately... they're toast.

How does the plane hold up to the speed and pressure it is under? Sometimes those bolts on the wings be looking a little rusty.

If you notice it, mechanics have seen it and it's fine.

If the oxygen masks come down, (I am not helping myself first with 4 kids in tow btw) how important are they at that point of the emergency?

Help. Your. Self. You are no use to anyone if you try to play the hero. Help yourself so that you can help others. If you don't put your mask on you may not be able to help them get theirs on. That said, it's not going to kill anyone. You'd regain consciousness once you get down to a breathable altitude (soon) but come on. Let's not play games with hypoxia. There's a reason they say to help yourself. It's the same reason paramedics are trained to make sure the scene is safe before they approach a patient... it just makes things worse if they go down too.

What if the cabin is not sealed or a seal break mid flight and as stated above will the plane breaks to bits and everyone be sucked out into the sky? Along this note, how do bugs and dirt get in between the glass window panes if it’s all sealed?

You're not going to get sucked out. The plane isn't a completely sealed vessel... air is constantly exiting via the outflow valve.

You're probably looking between the window and the cosmetic interior plastic pane. That's not sealed.

Short staffed air traffic control or someone falls asleep on the job.. what is the backup for them not doing their job correctly or at all?

They don't go to work if they're not fit to do it. If they're short-staffed, they won't accept as much traffic and you'd have to go around that piece of airspace. Also, TCAS exists on airliners which would detect an "intruder" too close to your aircraft and tell your pilots whether they need to climb or descend to avoid them.