Huh?
Spokes are not dished. What does "straightforward like on a front hub" mean. Your 2 questions make 0 sense. Try again.
C'mon now - the terminology is a little off, but the meaning is clear.
The wheel will not need to be dished. A "fixed/single speed hub" is the same as a flip-flop hub. Any hub you get specifically for fixed / SS riding will have threads on both sides and not require dishing when built.