Theo,
Would our immediate recommendation be to cull out as many of the GSF as I can before the rest of the stockers arrive, to better give an even footing to all species?
Little GSF (say, under 3") should make forage for your predators (like those 5"-7" WE). I can see making an effort to remove larger GSF (who knows what size GSF can eat an adult FHM?). If you plan to manage for trophy GSF as many of the exalted (read "disturbed"

) members of the GSA do, a slot limit would be in order - leave the small GSF, remove the medium sized, leave the very largest. You won't get them all out (even if you had longer), but you can make a little difference and have fun to boot.
Should I stock any RES in the pond? My local fish guy has some in that are 4-6". Would it be to my advantage to have any in there to control parasites?
Heck, yes! They will provide an additional forage source and control snails, and I doubt they can make your management situation any harder. Plus, if you're man enough to manage GSF, you might be able to handle Redears.
