I don't see swarm as useless. Some of the Pokemon listed aren't too great in general due to their horrible stats. Swarm actually helps them using their already poor stats to boost the ability faster.
Illuminate raises the chance to find Pokemon in the wild. It has its bonuses even if its not for battle.
Kluts has benefits for item switchers. You can easily mess someone up by sending out a Kluts Pokemon with Choice item and force switching the Choice Item to the opponent, or even using Fling. Give the Kluts holder an item that is usually bad for it like Toxic Orb or Iron Ball and Fling it at an opponent.
Normalize loses SE but gains STAB. With only 2 resistances which even out the damage, Normalize makes it easier to bypass a lot of other issues. It has its own perks if you are willing to overlook the set back of no SE hits.