It all depends on your classification with the company that you work for.
For defence of personnel and property.
Maybe. Local laws may differ. Some places armed private security is allowed, some places it isn't. If it is allowed by law, the particular security company policy will determine if a guard is armed. Usually guards are armed if they are transporting items of high value such as cash deposits.
The rules on whether security guards are required to carry guns varies from state to state and job to job. When applying for a job as a security guard you will be able to find out if this is a requirement of that particular role.
Yes
Most can. It depends on their particular state restrictions.
There is no full form of security guard. You can have a private security guard.
There is no full form of security guard. You can have a private security guard.
Depends on the definition of unarmed. Sometimes they can carry a taser, and sometimes they can't. At the very least, they have a pair of handcuffs and a radio
Church security should carry a firearm within the same parameters as any security guard. Most security jobs have the possibility of involving use of force, and if the security guard has to defend his life, having a gun would be a great advantage. If you mean should they carry firearms because they are at a church, being at a church does not preclude the possibility of needing to defend your life. Also, the Bible says in a couple of places that self defense is acceptable.
A security guard does not need very much training. It typically just takes one class during a semester to get what you need. Unless you carry a gun then you need gun training.
No all security jobs require you to carry a gun. Some security jobs at the department malls or schools actually forbid people from carrying guns. Most security jobs are what people call "flashlight cops." They usually only carry a flashlight and keys, no gun. There are armed security guard positions though.
If you are a police officer or security guard. if you carry a baton out in the open most people won't care. if you carry a baton in your pocket you will then have a concealed weapon.