As I read in the rules that hostility is placed on my board, in the war zone.Yes.
1. My friend has the ability in his area of hostility to obtain success at the end of the game (the checks in his zone of hostility). Even if you do not have any fortune or reputation token that check counts as a success and can reduce hostility? or does that check turn a failure into success?You roll a die for each reputation or fortune you have left at the end of the game. The mark your friend has gives him one extra automatic success. You can 'spend' those successes to remove one of your enmity tokens from anywhere -- provinces, islands, etc. You can also remove (cross out) enmity stickers, but that costs two successes each.
2. If the game ends that same round, what do I do with the hostility of the war zone? Where do I place stickers? Are the effects for the next game lost?Enmity tokens on anything you own (the 'at war' box, your fields, or on anything else you own) turn into stickers places in your provinces enmity box (on the board).
3. Another doubt arises with looting in the rival region, if I loot a field of cultivation of the opponent with 1 defense, I must give a token of hostility that he places in his field, and after the winter he places it in the zone of war.If you have any of his enmity tokens in your 'at war' box, then you pay the cost of raiding out of that pool first, then out of your own tokens if necessary. He puts his own enmity tokens back into his supply. If you paid any of your tokens, then they go on whatever you raided, but if you were able to pay for the raid out of his tokens, then nothing gets put on the place you raided.
4. If my friend attacks me in the future, what hostilities will reduce his number of dice.Any of his enmity on anything you own (your fields, your treasury, your 'at war' box, as well as any of his stickers placed on your province. Each of those reduce his dice pool.