The FAQ wrote:
If a monster has bonuses like "Shield" or "Retaliate" on their ability card, is that active for the whole round?
No, bonuses only become active once the monster takes their turn based on the initiative on the ability card. It then lasts until the end of the round, where it will either get shuffled back into the deck or replaced with the next round's ability card.
No. Only if sufficient range is specified.
The rule book, page 26 wrote:
A “Retaliate X” bonus ability causes the recipient to inflict X points of damage on figures who attack it from an adjacent hex for each attack made. A retaliate bonus can also be accompanied by a “Range Y” value, which means that the retaliate damage is applied to any attacker within Y hexes.