Security Clearance

[not perfect]

How tough is it to obtain a clearance with an expunged record? are you automatically disqualified because of the alcohol related offense or?

 

[FlyingRon]

The expungement will not hide the offense for your security clearance application (you must report it and they'd find out if you lied anyhow).
Whether the offense is disqualifying depends on what clearance you are up for and what the nature of the offense was.