1.Front stage should always come from in front of you... so C pillar pointing forward would not be a good idea.
2. 2 kinds of correct tweeter alignment, on-axis or off-axis. From your "pod" description, sound like you are trying to go for an on-axis setup. Both pods would ideally be pointed at the drivers headrest, giving a good on-axis alignment, and then time delay would be used to delay the drivers side so the sound would reach the headrest at the same time. This makes it a little less optimal for passengers in the vehicle, as they are all in off-axis positions and the delay may be noticeable. If no time delay is available in your headunit, the compromise is to align (point) them at the center of the vehicle between the 2 front seats. Technically this is now an off-axis setup, but still will give good results (even pointing at the drivers headrest, with no time delay, will give exceptable results.
Otherwise, off-axis is the way to go. Basically pointed straight across the vehicle. I find that the higher the better in this configuration. Pillars almost always sound better then low on the doors.
3. I personally haven't heard many silk dome tweeters that sound "harsh". Running them at full RMS shouldnt be a problem. But it is much easier to over power and distort silk domes, rather than aluminum dome or bullet (horn) tweeters.
I would run both sets on the a-pillar, pointed at the drivers headrest, if it were my setup. Crossed correctly with the right mids (you never really said if you were pass banding and amping the mids, but I definitely would as this is really shaping up as an active setup), should be plenty to keep up with a single 18".
2005 S10 Blazer 2-door
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