1-Although I'm not quite sure when you would want to apply the filter, you can test that the filter is loaded properly by using the following trigger:
Event
Player - Cinematic skipped
Actions
Cinematic - Fade Filter
for the options in the fade filter, make them match this:
fade out and back in over 5.00 seconds using texture fade1.blp and color (100.00%, 100.00%, 100.00%) with 0.00% transparency
Have your imported filter's name set as "fade1.blp". This may not be exactly what you want, but it is a good place to start playing with the options. You could change the events so the trigger happens at different times (maybe apply the filter when a generic unit dies).
2-To make impale a passive spell, it is impossible to do this in the object editor. I have never actually done this kind of change to an ability, but hypothetically, you could check if an enemy unit comes within range of the caster, set up a condition checking distance, and run a set of triggers that add the ability, orders the ability to be cast and removes the ability. Or you could use a dummy caster. Either way, I don't like it and it would probably leak.
A little off topic, your post is still quite cryptic. Good job on the colour. And what picture do you want as a filter?
