I have 3 countries that contribute very poorly to my budget South Africa (1000), Indonesia (4000), Ireland (1000) with 0 monthly increase since the start of the game. I'm in November 98... Winter is coming.
Don't pay too much attention for it. Be sure to maintain average score to gain maximum amount of monthly income (>2000 score = increasing for 15% from last mont income) and everything will be okay.
These countries are under radar coverage.
It does not really matter. If you will skip some missions on the territory of certain country, this country can decrease it's funding (if the score is too low, of course).
Each base has 1 long range and 1 short range radar.
Only ONE radar system works at the same time, so you no need to maintain more than ONE radar system on each base. The difference between them is about percentage of UFO detection. Hyperwave decoder has 100% chance to detect UFO.
Are the governments infiltrated from the start ?
No. They can be infiltrated from January of 1999 - when the invasion starts (the same situation about alien bases). If the G. was infiltrated you will see the message about it in the monthly report.