Difficulty and negotiation

[Quitch]

Two questions which I couldn't find answers for in the manual:

1. What is the difference between difficulty levels? Smarts? Resource bonuses?

2. On the negotiation screen there are three icons, the middle indicates whether they're allies or not, the right one the current state of relations (which seems to reset when they change from neutral to ally) and I assume is how close you are to moving up or down a level, but what is the left icon (starting at cautious)? Is that influenced by how often you keep or break deals? What does it affect?

Also, a quickie, I sometimes see that player X has declared war on Y, yet they're not at war when I check the relations screen. Why? I'd have thought perhaps it would be that X declares war and then Y makes peace, yet since this is a we-go game is that actually possible inside one turn?

[Iceman]

1.

Easy
Security +2
Player Combat Modifier x 1.15
AI Combat Modifier x 0.85

Hard
AI Tax Income x 1.3
Player Tech Costs x 1.2
Security -1
Player Combat Modifier x 0.85
AI Combat Modifier x 1.15

Very Hard
AI Tax Income x 1.6
Player Tech Cost x 1.4
Security -1
AI Security +2
Player Combat Modifier x 0.8
AI Combat Modifier x 1.2

2.

The ones on the right indicate how much they like you. If they don't like you, they'll require a much bigger profit in the deal than you get.
The ones on the left are about how much they trust you to meet your obligations. If they don't trust you, they'll value payments over time very low, and won't make defensive alliances etc.

[Quitch]

Thanks!