Army and Marine corp can give 'moral waivers' and allow a person with only 1 felony conviction to enlist. If more than 1 conviction you are SOL for army or marine corp. The air Force and Navy allow waivers for multiple convictions, but waivers are a lot harder to get in these branches of the service.
Legal discrimination.
no
Army depending on how badly they need personnel.
What are the healthcare restrictions on joining the british army
Sixteen is the minimum age for joining the Nepalese army.
yes
There is no restriction on joining the Salvation Army.
The process in joining an army barracks include enlisting and finding the right capacity in the army. One can go to the Army Careers Center and seek advice from a Careers Adviser.
Scutage
Some people feel passionate about joining the army out of a recognition that the country needs their help, or even that the world as a whole needs their help.
no sons
No, they cannot.