not every civilian. If i remember correctly - after reading about amateur launches of like 10ft+ rockets - you have to have some kind of explosive related license to enjoy such rockets.

Yes, different licences for different impulse classes of rocket motors.

More details can be found on the National Association of Rocketry website (http://www.nar.org).

Level 1[1], Level 2[2] and Level 3[3] certifications.

[1] http://www.nar.org/high-power-rocketry-info/level-1-hpr-cert...

[2] http://www.nar.org/high-power-rocketry-info/level-2-hpr-cert...

[3] http://www.nar.org/high-power-rocketry-info/level-3-certific...

Not really, though many stores will refuse to sell to you without an NAR certification. You can make your own or just be good friends with the store owner.

A guided missile is a type of arm, what's the problem?

I dunno, I have hands on mine, but whatever, if you wanna be flashy...