I frequently open a file by double-clicking on it from file explorer. phpED is opening it, but it remains in the background. I'd like it to become my current application (receive input focus) when a file is opened. Is there a config option for this? Seems it used to do this before I recently upgraded.

It's the OS behaviour. If you want to change it, get you Windows disk and install tuning utilities. As I remmeber, there are some tweaks that allow an application to bring itself from the background. By default it's not allowed. See MSDN/SetForegroundWindow API function notes for further details: http://msdn.microsoft.com/en-us/library/ms633539(VS.85).aspx