On one planet, I have almost 50k surplus, from 80k - so PD should cost me 8k. I see no reason at all why it should be offline. 
Same. That is quite odd. Was there a large trade on that planet that turn? That's the only thing that messes me up now.
I'm sending almost 200 cruisers to a planet with 3 mio. people, society 49 - and my surrender chance is 10%.
I think the chance is supposed to increase quite a bit over time as you kill people with your orbital bombardments, sway them with your big pointy sticks and generally make them give up on life under their former rulers. How much it increases and if it makes a difference is as yet unknown, but I think Dave said he might tweak it once people have had a play.
