Dorne - 1st attempt

Your non-setup suite is a little big compared to your limiteds, and huge without any draw. If they were a bit more balanced you could avoid having to run marching orders. If you really want the high raw-gold, trading is in fashion atm.

 

Switch a quentyn to an arriane, you have a ton of targets for her, and he's fated to die/more expensive. Maybe downgrade the paramours to a 2-drop neutral. Wildling scout? Put in your third greenblood and you're in business.

Doran's Game x2 - it's not a card you want to see in your opening hand or the early rounds. Roseroads are crucial for set-up and sustainable economy. Counting Coppers is necessary for draw as Martell currently has no draw engine, another reason for adding the 3rd Trader. Consider His Viper Eyes, a very efficient card especially if going first if you want to get rid of PttS since first player has first actions.

All the above things that guys said, and a few words from me. Regarding plots, try to get as much initiative as possible, it matters a lot for Martell. For example, Wildfire and Clash of Kings instead of Filthy Accusations and Marching orders. A Game of Thrones and Calm are good but you should consider Counting coppers as Magnus said and Heads on Spikes as it has nice gold and initiative and synergy with Ghaston Grey. Long Plan is also a good opener as it has good reserve for preparing you for later turns.

Syrio and Quentyn are fine as 1x, replaceable with 2xDoran, he is good if played at the right time.

You need to reduce either number of attachments or events, never go above 15 total and it should probably be 10-12 max. I'd keep 3xMilks.

If your friend is playing aggressive deck, get those Bastard daughters, Greenblood Traders, Ghaston Grey, Milks in play, time your Wildfire right, he'll soon run out of steam. And of course, have fun!

Another thought.  If your opponent is using lots of high-claim plots, Vengeance for Elia is great for avoiding board-wipes and reversing the pressure on military challenges.  This does place more demands on your economy so the Roseroads would be a must, as well as considering another high-gold plot.

@bored2excess - on nonsetup vs setup I am drawing anywhere between 4 and 7 playable cards. With 3-4 cards that I can get out of my hand on the setup. Dont know how this compares to other decks, but it doesnt feel like the worst thing. Especially cos i'm packing so many cards that slow down my opponent right out of the gate. 
As for Arriane, I was thinking that +1 STR and stealth with Quentyn was better, particularly as I've decided to take out Syrio now. But, you reckon the ability to surprise-play characters outweighs that? 

@MagnusLothar - I was over drawing on Dorans Game, so I have cut one of those. As for draw. I've mixed up the plots a little. So might have room for a Countin Coppers. But I'm really in love with having 5 plots that can slow down/ mess with an opponent. Is draw really that valuable?

 

@NikolaP - I did consider the lack of initiative, but with so many events/attachments/locations/plots that can mess with an opponents challeneges ability, I didnt feel it was too much of a loss. Break it down for me? 
As for opening plots, I've been playing a back-to-back Filthy Accusations. Its so satisfying. The opponent will spend 6/7 of their set-up cash on a Tywin or an Eddard, and just not get to play them for aaages. Its a lot of fun. 

I was over drawing on Dorans Game, so I have cut one of those. As for draw. I've mixed up the plots a little. So might have room for a Countin Coppers. But I'm really in love with having 5 plots that can slow down/ mess with an opponent. Is draw really that valuable?

 

 

In 1st Ed there was a general consensus that draw=win, and some decks (notably Martell Bloodthirst decks) could end up with obscene amounts of cards in hand.  However, board presence is currently more important in 2nd Ed - but that's not to say draw is not important.  You need it to keep your options open.  It's awful top-decking by turn 3-4 when your opponent still has 4-5 cards in hand.

 

Depending on other plot choices, the low gold offered by Coppers isn't too painful.  A common ploy is to precede it with The Long Plan: 8 reserve from that plus whatever gold you carry over, then a whopping 10 reserve for Coppers.  Suddenly you have card advantage...

 

The Traders are a trade-off, unsurprisingly.  They help to thin your deck, but sometimes give you an awkward choice in terms of which card ends up bottom of deck.  They also like First Snow...

 

Other than that you're left with Doran's insight and search effects from plots.  Doran works best in Fealty decks where his high cost can be somewhat offset; and unless you plan to leverage his ability on TRV, Quentyn etc. it's a big ask to run him more than 2x.