jeez buddy that is some list there but at least it is all fixable.
you mentioned a while back that fuel economy was now more of a priority so fixing the sport would be the better long term option, however fixing either, in my mind, means a long term commitment as they will both owe you in outlay.
I would have to re read but I seem to remember the possibility of taking some of the good stuff ie brakes from the WRX to fit to the sport so that would help support some of the improvement but that would still leave you with a WRX which needs attention or that will need breaking to recoup some funds or you bite the bullet and just scrap the WRX.
what would I do
fix the wrx and sell it try and at least break even
take anything worth breaking from the sport to sell possibly store it in the empty space from the wrx.
then go shopping for a sport in the colour you want etc but without the rust etc of this one