Hi Brian, well come to the club. I presume you are using the 3rd Edition rules. Should you be interested, you may download the
4th Edition rules and charts from APL. There is also a
demo game available to order and for online play. Both are free purchases, but the physical demo game requires shipping. There used to be a DIY version available. Onward...
Limiting Terrain Spotting range is 3 hexes, unless otherwise specified or curtailed.
Assaults I am not entirely clear on what happened, but I'll take a shot. The leader in the adjacent hex should have been able to activate the units, or the leader, in the assault hex.
Leadership outside the assault hex may not activate or influence units or leaders in the assault hex.
Town/Village Yes and no. Yes, all modifiers are cumulative. (DF does have limits on the total modifier applicable.) No, you
may not dig in town hexes.