Can my new MP9 be upgraded with an external lever and internal lock like the MP45?
I've never owned a semi-auto and feel uncomfortable pulling it out fast from the holster knowing it is armed without any trigger safety. I am a rooky I guess............
Please do practice your gun handling skills, including drawing from the holster and take a class or two so that you learn to do these things correctly. Most importantly, when you practice drawing and other manipulations, practice with an unloaded weapon.
Remember that if you follow the four rules, especially the one about keeping your finger off the trigger until your sights are on target, you cannot have a negligent discharge. Guns don't spontaneously fire by themselves.
I have been told that some carry the semiauto without a cartridge in the chamber. They draw, then cock with slide and shoot. Is this a good idea?
Here is a something that I've heard others suggest for those who are squimish about a loaded chamber:
With the magazine out and the gun unloaded, rack the slide and let the trigger get in a "firing position".
Insert magazine.
Put the gun in your holster of choice.
Carry it in that condition as you normally would. At the end of a week, take a look at the trigger and see if it has been accidentally "fired". Chances are it will still be in the exact same postion. This should get your confidence up.