It’s been a while since I checked in on the Exult Rotate thread at the Exult forums, and I see that late last month, Dominus and cma identified and corrected a bug:

Try change this:
gwin->paint(gwin->clip_to_win(rrect));
to:
Rectangle crect = gwin->clip_to_win(rrect);
gwin->paint(crect);
insteads and see whether it helps.

For the Alt-t cheat. look inside cheat.cc and add new code after the call to screen_to_game

void Cheat::cursor_teleport (void) const {
if (!enabled) return;

int x, y;
SDL_GetMouseState(&x, &y);
gwin->get_win()->screen_to_game(x,y,gwin->get_fastmouse(),x,y);
(new) if (gwin->rotate) gwin->map_to_rotated_map(x,y); // convert to rotated world

Which, according to Dominus, seemed to help:

I didn’t try anything new out except for getting your last v3 patch and with that all my problems (except for the makefile.am one) are solved.
No compile problem, no dragging ghost on original spot and teleport cheat worked fine, too.

Dominus put together a new OS X build as a result, which can be obtained from the project entry here or the Exult forum thread. I’ve decided to label it as version 0.3, since that was a version previously unavailable for OS X.