On Each Board With Invaders: Add 1 Blight to a land with at least 2 Blight, but do not cascade.
if a land have only 1 blight, (this blight is only one of that board), i add 1 blight to that land?
is this 'as much of the card`s instruction as you can'?
Sandfever Outbreak
On Each Board: Add 1 Disease to the Sands or Mountains with the most Town / City (minimum 1).
if a board`s snads or mountain`s have only explorer, that board can`t add 1 desease?
Blight Spreads
On Each Board: Add 1 Blight to a land adjacent to a land with Blight. Spirits may prevent this on any / all boards by destroying 2 Presence from each board to be protected.
if a board don`t have a land adjacent to a land with Blight, what`s happen?
Distant Hunt
On Each Board: Push 1 Beasts to an adjacent land with no Blight. It deals 1 Damage there.
if a beast can`t move, what`s happen?
Reprisal Against the Dahan
On Each Board: choose a land with Dahan and Town / City. Invaders do 3 Damage to Dahan there, ignoring Defend Powers.
is invaders do 3 Damage to Dahan there (per land) ?
If there are no relevant lands on a board for an action during an Event, you just skip that board.
Festering Pits of Blight - Yes, if there are no lands with two or more Blight, you can't select one to add more Blight. Yay :D.
Sandfever Outbreak - Again, yes - as it specifies "minimum one" of Towns/Cities, if there are no Sands or Mountains with at least one of either, you add nothing. Explorers don't count, as they aren't mentioned.
Blight Spreads - If a board has no lands adjacent to a land with Blight (even if the Blight-containing land is at the edge of the next board), I'd say you were doing pretty well :D. But yeah, again, as there are no lands that meet the critera, you just skip it and do nothing on that board.
Distant Hunt - If all the lands adjacent to the Beast already contain Blight, it can't move, so it doesn't.
Reprisal Against the Dahan - As usual, you take each board one by one. On the first board, you look and see if there are any lands that contain both a Town/City and a Dahan (doesn't matter how many there are of each, only that the land contains at least one Dahan and at least one Town/City). If there are no such lands, skip that board and move onto the next one. If there is only one such land, the damage has to be dealt there. If there is more than one land that meets the critera, you would pick one (as the Event card says "choose a land") and only deal the damage there, then move onto the next board and make the same check.
That's my understanding of it all, anyway. Hope that helps :).
Ameena has it exactly right! On Distant Hunt, I'd add that if a board has two Beasts, and one of them can move by the rules and one of them can't, then you have to move the Beasts that can move.