ABL is usually associated with Standard or Eco Modes as it is a way for plasma TVs to conform to Energy Star standards. What size do you have? The larger your TV the harder it is for it to hit a high brightness as this is a side-effect of plasma technology, and the only TVs we've seen that can maintain brightness on a white screen is the Pioneer Kuro and the Samsung F8500. Unfortunately there is little you can do to increase brightness beyond using our settings.

The flicker is a separate issue and not something we've seen occur on this TV, are you using 3D mode?