Sadly things are never simple.
First we need proper passenger and staff screening to stop anyone getting to the aircraft in the first place,this means governments and airport authorites spending serious money...
As a 757 capt with a European airline I can assure you the door on my 757 is the same as in a US airliner, but we had to pay full price for ours.....
Guns..I enjoy shooting and am pro guns in general, but I agree wil Les on this,partly from a practical point,if some one breaks onto the flight deck i'd have to get the weapon,ready it, aim and fire, being right handed and in a confind space i'm not sure it would work.
There's a good dicussion on www.pprune.com
If the "authorities" think there is a risk to a particular flight why let it depart?
Many aircraft have the gear sequenced to take the load of the hydraulic pump(s),It's 20 years since I flew the KingAir and I can't remember the tech details..
I'd guess you are in the minority,I fly for an airline and the majority of people I fly with have at least a passing interest in cars or bikes, should there be car articles in Flying is a whole differnt question!
Bob