If Roark uses his ability on a ship that has Swarm Tactics that ship can buff another ship to PS 12.

If Roark is within range 1 of the ship that he buffs up, could that ship use Swarm Tactics to buff Roark to 12?

Sure can.

Indeed. I saw a very effective force with Roark (ion turret), Wedge (swarm Tactics) and two rookies - able to get three X-wings all at very high pilot skill, or to chain two of them to PS12 if there was another PS9 pilot floating about.