Please correct me if I'm wrong, so you look at the condition of the sign-ruler, then use the quadrant system to look where the cusp falls to determine the capacity of that ruler? You can have an exalted sign-ruler but if the cusp-ruler is debilitated it's unable to act.
This really depends on whether you do modern western astrology, traditional western astrology, or some hybrid. In modern astrology angularity does not confer any particular strength: each house has a kind of stand-alone interpretation. None is particularly good or bad compared with the others.
In traditional western astrology and the horary astrology derived from it, the 1st and 10th houses are extra-strong; followed by their opposite houses. However, the 11th 9th, and 5th houses are also favorable. The "bad" houses are the 6th, 8th, and especially the 12th.
We do look at house cusp rulers in both systems. In modern western natal astrology, most of the traditional dignities and debilities are ignored. Each planet is seen as operating according to the nature of its sign and house, but not in a stronger or weaker way. The one exception I make as a modern astrologer is that I think domiciled planets, or planets in mutual reception, are extra strong.
The essential and accidental dignities and debilities are more important in horary astrology. It matters in many questions which party's significator is in a comparatively strong or weak position.
It's hard to say that planets are utterly helpless. But in traditional and horary astrology, there are definite strengths and weaknesses. In the latter cases, look also at whether aspects are applying and separating; and whether a planet (notably the moon,) has made its final aspect before changing signs.