Ok, I've verified that all of the live-tradeable IBFX pairs are also available on the FXCM datafeed (from here: http://www.fxcm.com/products/forex/currency-pairs )

So I believe I only need to determine whether or not the Assets.dta and AssetsFix.dta need to be in the FXCM format with the slash (ie, EUR/USD) or if it is acceptable to leave them in the IBFX format (ie, EURUSD)

If the slash is required, then it should just be a few simple changes to the Zorro.mq4 script as noted above.

How should I go about acquiring history testing data from FXCM datafeed for the remaining pairs? On IBFX there are 27 pairs that I follow. Is there a place to download individual tickdata for each pair from IBFX? If not I can get it from another source, but I prefer to keep it consistent as possible.