If you are opposed to driving to CHS or CLT...

What about:

CAE-IAD-EWR? On UA/CO

Or

CAE-PHL-EWR on US

Or

CAE-CLT-EWR on US

Or

CAE-LGA on US (Once Daily)

You'd still earn miles with CO for all of the above, even earning 2x segments, if you qualify that way. I know you were in favor of a non-stop flight to Newark, but sadly airlines, no matter their size cannot have a flight from everywhere to anywhere.