Crime, Government, and Cabinet ability bonuses don't work/do anything.

Rush buy cost is calculated as:
Rush buy cost = ((base cost - already_spent_points) ^ 1.1) * 6
The interst rate is then calculated as a percent taken off that number. So a 25% interest rate should make things you rush buy cost 25% less.

War profiteering lets you get a % of each civ's total income if they're at war. So say the Terrans and the Drengin are at war with eachother, and you have 10% WP ability. You would get 10% of Terran's income plus 10% of Drengin's income. You can see how profitable this would be if you played with 9 major civs and 8 minor civs, and bribed a few so all 17 are at war with someone else.

For the Presistant Trade Routes, I think best explaination is just a copy-paste from the Freighter Command improvement which gives that ability:
"Normally a trade route is ended if the mini-freighter between two planets is destroyed too many times. With Freighter Command, you receive an unlimited number of mini-freigthers." (Yes, that's a typo in game... freigthers ! lol)
Why the number is in the millions/billions I'm not sure. Can't find anything about why it's so high anyhow. I've never hunted freighters as I've always just bribed 2 civs to goto war with eachother to end their trade routes, so I don't know if they just 'gave' that ability to each civ and that number represents the # of freighters you need to destroy or such.

Kryo might be able to shed some light on that oh-so-high number if they get around to reading this.