Greetings

I have few questions about gameplay.

First of all: I need a BASE maximum tax revenue from 1 bilion of population (this means teoretically 100% tax rate and NO bonuses of any kind).

Second: What is this growth cap because of low PQ that I keep seeing in other posts? Does it mean that planet with PQ 4 and 20mt food prod can't sustain 20B of population? Or just that it will grow slowly?

Third: Is there possible to see summary of ALL bonuses to my civ, that mean including party, racial, abilities and techs? (I'm not playing right now so I thought I'll ask)

That would be all... for now.