Yes, balancing the light needs of the plants with making sure the Paros still feel secure is potentially tricky. Metal halide lights are quite powerful, but importnatly are also better able to penetrate the water than normal T5/T8 lights. Having the light 2 feet above the tank allows enough light for the less demanding plants to grow, without being so bright to scare the gouramis (I tried some more demanding plants (glosso etc) but they did not do well).
Having the light angled from the back of the tank also means I can keep floating plants around the front edges without blocking the light from reaching the other plants, which keeps the paros happy :).
This tank really is all about compromise and balance… it is not the perfect paro tank, nor the perfect plant tank, but taken as a whole it seems to work – which makes me happy, as the whole thing was a bit of an experiment and could have gone horribly wrong!