Assault is only classed as 'moral turpitude' when it is
(a) with intent to kill;
(b) with intent to commit rape;
(c) with intent to commit robbery;
(d) with intent to commit serious bodily harm; or
(e) with a dangerous or deadly weapon.
The Foreign Affairs Manual of the US Department of State specifically states that an assault "which does not require an evil intent or depraved motive, although it may involve the use of a weapon, which is neither dangerous nor deadly" is NOT 'moral turpitude'.
http://www.state.gov/...rganization/86942.pdf
Your conviction for ABH might still result in you being refused a visa. The only way to find out is to attend the interview and to see what response you get. However I can see no reason why either your age or your employment history should have any adverse effect upon your visa application.
Chris