FoA's Pulsars: The reasons for the Keel allocation are because there are no port or starboard criticals for eldar hence why no other eldar ships have port or starboard weapons, also the fact that the pulsar strength is unaffected by circumstances that would halve thier firepower. Note: There's no change to thier arc, they still shoot forward.
Eldar Hero: The reason for the drop in price is quite simple, he's comparitavely too expensive. The Pirate Prince costs 100pts and is Ld10 unless a 1 is rolled, the Supreme Admiral costs 100pts and is Ld 10. The Hero has more expensive re-rolls than the other 2 unless he buys all 3. The ability to have reserves is rather limited as you will need to buy an extensive amount of the weaker parts of your primary fleet to field the best parts of the other.
Shadow Hunter: If they are going to have a bonus ordnance killing rule it should be close range as they don't have special weapons, they have special movement. Shooting AC even 1cm (1000km) away can't demnonstrate hightened manuverability! Giving them 3 turrets is simple, useful, true to background and isn't even a special rule.
Cheers,
RayB