just to make sure, I can still drive to school or work if I'm an A2 problem driver, right?
Yes, you may drive to and from your place of employment or education when required.
if I'm driving for employment I need a letter from my boss, right?
If you have an ignition interlock restriction your employer must provide you with signed documentation, on company letterhead, saying they have knowledge of the ignition interlock restriction.   The letter must also give you permission to operate the vehicle for business purposes without the device.