You wouldn't summon Swallow via effect, you make use of your extra summon from Tensu. It's not hard to get it out either when you search it with Rooster.
Also yes, Divine Wrath does not target.
Excluding 4-axis, is the use of Tensen completely necessary in the 3 or mixed builds? I know the build that was running TKR and Mistakes did not run them and had pretty good success. Have any of you had times when Tensen felt useless by itself when drawn or opened up? Sure, Rooster swaps out used Tenki/Tensus for Tensen but from what I have tested I always wanted Gyokkou because I can use it that turn or I save it so that my opponent does have to worry that I can lock down a card next turn. I feel as though if you don't run Dragons or Swallows in any Fire Fist build then you may not need to use Tensen and go for protection or other cards that cripple your opponent. Being able to play Tenki, Tensu, and even Gyokkou without having a monster on the field is something that Tensen lacks.