I don't think that we need less debuffs, actually I would like more of them. There's only 2 issues atm: numbers and durations.
What I'd see is smaller stacking debuffs scattered amongst more professions. So 1 player could debuff but it wouldn't be as crippling as current debuffs. 2 different professions debuffing the same skill would hurt you more.
Also I see more and more uses of % instead of raw numbers in other games. That's a direction FC should follow a bit more imho. Or more skill-based effects. Easier to balance across all levels but will reduce the number of nanos.