A few questions from a newbie

[Alneyan]

I would like some answers for a few questions from your average newbie in various areas. Here are the questions.

1) Do the planetary and the system-wide bonuses for research for instance stack? And if so, is the bonus of 60% (30% and 30%), or of 69%, almost 70% then? (30% of 130%) I know bonuses do NOT stack for other facilities, but I am unsure about research facilities.

2) How efficient is the bonus to population happiness granted by the Fate Shrine compared to the regular facilities? The ability reducing the chances of bad events seems to be working, but is that ability really useful?

3) Can you use drones efficiently? I don't seem to be able to give them proper targets and they are usually wasted, which is rather annoying as they cost a lot. (Compared to other units at least) And a drone destroyed when chasing its target isn't doing much good.

4) Can you know the composition of a satellite group? Even after I send a suicidal scout against them, I only know there is a "Satellite group" without knowing the design(s) used, except of course if these are the first satellites I encounter. (I can view the enemy units design then, but it won't work after a few battles)

5) Lastly, are PDC used as soon as seekers/fighters/drones are detected or during their turn? Let's say cruisers with PDC are attacking a warp point defended by a few fighters, are the fighters shot before they could fire, or do they have a turn before being destroyed?

I didn't find any answer in the Newbie FAQ and searches on the forum weren't successful either. My apologizes nevertheless if it is the 104th time you see these questions.