Desert Wilderness

I'm not sure about this. I have never played or seen in play a martell wildling deck (or a lcg wildling deck for that matter) so maybe I am not the one to give advice. However I don't think there is a lot of synergy between those cards, or at least I can't see it. And it's not like they are all super-Jaime-efficient on their own.

It wouldn't hurt to try this deck out though, but first I would change few things.

• I'm afraid, that you have too few targets for Bodyguard to run it. I'd cut it. Alternatively you could add more lords/ladies, here are some interesting choices: Ser Archibald Yronwood (CD), Ser Gerris Drinkwater (CD) (good keywords and STR for the cost, and ok abilities), Jalabhar Xho (ODG) (good synergy with Burining on the Sand and your revenge strategy), Ellaria Sand (PotS) (she's awesome). I think that you may have too few targets for Oberyn's Guile as well, so you can kill two birds with one stone here.
• Your economy seems way too weak to uphold all those expensive characters. Doran Martell (TGM) is extremely overpriced in my opinion BTW. And talking about overpriced - Arianne's Conspirators and Wildling Mead (in this particular deck at least) fall in the same category.
• Someone Always Tells is pretty cool, but again - it seems that more often than not you won't be able to pay for it. If you don't want to cut it add more influence and then consider adding one The Viper's Revenge (EB) as it helps to trick your opponent into leaving many characters standing. Follow it up with Rule by Decree (Core) and you're set.
• Nightmares in the North on the other hand are not cool at all. I'd definitely cut x3.
• Other cards worth considering: Ghost of High Heart (WLL), Climbing Spikes (AKitN), The Viper's Rage (TftRK)/Red Vengeance (PotS) (depending on your choice whether to run more influence or not)

If you don't truly see the synergy of the deck then I will clarify, the basic idea is to control your opponents field enough and then bash their hand. The main ways that you can get this through is by getting out seal of the crown or just doing intrigue challenges. I get your point on the attachments, however I only have them in here because either: A ) they give protection on the two characters I need to stay alive even through a valar or B ) mainly with wildling mean combined with wildling wisewoman is very effective and shutting down draw on your opponent allowing you gain complete control over when they draw. This deck is a bit of an oddball, in being that it chooses when your opponent draws and then has ways to get rid of the cards out of their hand. The deck itself has good enough draw through "reveal and add to hand effects" that the downside on seal of the crown will hardly ever touch you. The economy is something that seems hard to notice, but after many sessions of play testing (15-18 games) I've found that it sits rather comfortably where it is at currently and can easily manage a 3-5 card setup at least every time.

As for nightmares in the north, I ask why you would cut this, because without an explanation I will have to submit to you my own logic into this. Nightmares in the North combined with seal of the crown, if you are doing well, can cause not only your opponent to lose several cards from their deck straight away but can force them to draw from their deck which triggers the seal of the crown, and yes I get that if you are winning you probably will be hit by seal of the crown instead, but with forcing your opponent to draw and discarding from their deck it becomes an advantageous spot for you to keep decking them and destroying their hand all in one fell swoop as opposed to your ordinary greyjoy discard deck this one focuses more on control and hand manipulation while burning through their deck.

I will be happy to further in depth if you would like, just let me know.

Regarding Nightmares in the North (RotO) - the fact, that you have already tested this deck few times and this card didn't struck you as a waste of event slot makes me wonder if I am not mistaken. Still, your argumentation didn't convince me, so let me respond.

You basically said this card lets you do two things: discard cards from the top of your opponent's deck and force him to draw a card. Nothing more. This is exactly why it's useless.
Let's talk about forced draw first - you have to keep in mind, that having Seal of the Crown (APS) in play doesn't make drawing a card a bad thing, it only makes it less of a good thing than it would normally be. Your opponent draws a card, and there are two possible scenarios: he drew a card that, at this point, is more useless for him than any other card he already had - he discards this card - basically nothing changed OR he drew a card that is more useful for him than at least one card he previously had, so he discards the most useless card in his hand - he's better off now.
Now let's consider effects of discarding cards directely from the top of the deck. If your metta at least vaguely resembles mine, joust games usually end leaving both players with more than half of their decks "untouched". This means that discarding few cards from the top of the deck will have virtually no effect on the game (unlike discarding cards from hand - even if the worst card is discarded it always narrows one's options). Or more accurately - it might as well have positive as negative effect for your opponent. You may discard something he really needs right now, or you may discard something else and make him draw the card he desires sooner, both events are equally probable. GJ mill is another story, because they have cards like Asha, Alannys, Baelor Blacktyde or other cards that trigger after the the top card of the deck is discarded.
So these were alleged advantages of this card. Now disadvantages are - 1. You have to discard top cards as well, which is not necessarily bad as I explained, but makes the card even more random 2. It "scales" with the number of cards in both dead piles - something you can't really control with this deck, which again adds to the randomness, making it extremely random so far 3. It is a Dominance: type of event, which is always a slight disadvantage on its own, as the card has to survive challanges phase. Consider opportunity cost of not having another card, that could be used in marshalling or challenges, as Nightmares can be discarded for claim before you have the chance to play them. 4. On the other hand it MIGHT give you one-time draw of 1 card, so the ratio is really bad, the effect is not guaranteed, and having Seal of the Crown out makes the ratio of cards gained and lost even worse.
Finally in the context of Seal of the Crown compare this card with Ghost of High Heart (WLL) I suggested might be of use for you. I won't elaborate any more, I hope you can see my point.

Sorry for the long post. I felt I really need to make myself clear (since our thoughts on this card are so different) and it was hard to be brief at the same time, because English is not my native language.

Understandable, but again I do see where you are coming from on the card, and I do tend to find that a bit of randomness and luck are large enough factors for me to consider adding a card to a deck, I probably will work around with this deck and I do see the use of ghost of the high heart and it will be relatively easy to work into the deck. If nothing else I tend to play more in a round about way and it makes the game more interesting to me, I don't necessarily make decks that are cutthroat or Jaime decks, but I play rather random and more unpredictable decks that tend to catch the forward thinking people off guard. I do enjoy your feedback, and if I do make changes to the deck I'll re-post it when I get some time after some testing and I'll let you know the results, and to me your english is excellent, so have no fear about doing long posts I'll still read them anyways.

Thank you once again Crow.