2) Can a single Turn of Shooting or Close Combat cause more than 1 Wound? In the Damage section, it says if the damage roll equals the target's Con, a wound is caused. But it doesn't say what happens if the die roll exceeds the Con. For every point of damage above the target's Con, is an additional Wound caused? Is this the same for both Shooting & Close Combat?
Yes, see the FAQ. If you roll above the target's CON, one additional wound is scored per point above the con. If more wounds are caused than health, then add +1 to the Injury roll. (ie. If you do 3 damage to a guy who has one health, add 2 to the Injury Table roll, thereby increasing the odds of a Major Injury.)
4) How exactly do you make a Resolve test? The Psychology section tells you when & when not to make the test. & what it's affects are. I assume you need to roll equal to or above the figure's Resolve since the stat is listed as 3+, but I couldn't find anywhere in the rules that actually said that.
Roll 1D6. If the roll is less than your RES score, you become insane.