They can, altho some gorgs have issues with SH repeatedly hitching to the same spot on them (assuming this happens). Also, most gorgs need a bit a flow, so you'd want to be sure there are lower flow areas for the SH if they feel like chilling out.
As for macro, most do fine with SH. Caulerpa prolifera is a good "seagrass" substitute, Codium does well at SH temps, Botryocladia is a nice red macro that works well under lower lighting, and Gracilaria or Cheatomorpha are great pod harbors (our SH dive head first into them to hunt).
HTH