Major bugs
Attempting to enter some taverns in Essos, namely
Volantis, Lys, Ruins of Ny Sarn or Norvos causes the game to crash to desktop, no errors or anything just an instant crash.
I suspect they may be using the same type of interior and the file is bugged or missing, tried unpacking the download a second time but that didn't help, maybe if I redownload, idk, anyway it seems I'm the only one with this bug, haven't found other references to it.
Tried to check all towns for it and I think I was successful in doing so, though since it's not always obvious from the campaign map which is a town and which is a castle it's possible I missed some.
Minor bugs and balancing issues
1)some helms have beards disabled and shouldn't; those I can confirm are:
open sallet, mail coif, cloth/leather hood
2)floating structure above the harbor area of White Harbor
3)similarly a couple of floating helmets above the graves at the Tower of Joy
4)an AI issue that's mostly to blame on native but still: Enlisted in Robb Stark's army; he spends 80%-90% of the time traveling between Saltpans, Moat Cailin and Winterfell saying he "needs to inspect his possessions", even though he has a 600 strong force he is completely useless, and I suspect he isn't the only northern lord with this problem. Maybe if he wasn't the lord of Winterfel? (I know it's bad for lore reasons but it's even worse for gameplay reasons)
5)the visored sallet armor rating is too low. It is in essence a full helm design that historically replaced the bascinet (like the houndskull or pigface bascinets currently in the mod) and was used in parallel with the armet. I'm thinking 60 rating for the variant that includes the lower face plate like all full helms and maybe 50 for the one without the neck and jaw protection, like the one you usually use for infantry, would make more sense.
6)speaking of full helms, I'm not quite sure about the 13th century models, they look too old fashioned compared to the rest of the gear, I don't mind it so much in tournament NPCs, but there are also some troops wearing them, like the Dorne serjants. I realize gear appearing in the show is inspired from equipment ranging from 13 to 16th century plus the fantasy stuff but this just seems a bit to much as far as immersion is concerned; granted this one might seem like more of a personal preference of mine.
7)mercenaries are terribly underpowered as far as gear is concerned; I especially have a problem with sellsword pikemen and halebardiers who are only equipped with a spear/halberd; they at the very least need a short weapon like a sword, axe or mace, as they are currently useless in tight spaces so no garrison duty or sieges for them, shields would also be a good idea; I'd also supplement the gear of the elite archers/longbowmen with a small shield or replace the sword with a two-handed weapon like a bill or mallet. Also peasant women have no upgrade tree, I imagine this is a bug since the peasant women as they are now are also completely useless and make no sense as mercenaries.
I'd expect northern archers to be longbowmen since their cultured is inspired more or less on English medieval culture as I understand it.
9)The spear vs horse mechanic is really poor, it's a good idea but poorly executed, it's not used to stop charges but it's more of a random weapon buff dealing extra damage to horses, as such I believe there should be the option to turn it off in the mod options.
10)You could really use some more diversity, at least visually, when it comes to weapons; plus there are some lore weapons missing, for instance there are no warhammers in the mod (think about Robert's hammer from the battle of the Trident). And there is a "gap" when it comes to swords between arming swords and greatswords. Greatswords have their uses, and arming swords are great for infantry but in between there should be some higher quality longswords/broadswords for cavalry and nobles plus the one-handed/two-handed bastard swords (there's currently only one 1/2H sword plus a hero item that I was only able to find while browsing the cheat menus).
That said here are some OSP pack suggestions:
lots of weapons:
http://forums.taleworlds.com/index.php/topic,277690.0.html
http://forums.taleworlds.com/index.php/topic,247595.msg5920747.html
http://forums.taleworlds.com/index.php/topic,268862.msg6434281.html
some more weapons (I think you might have some of the ones from this pack already but there's plenty more to choose from)
http://forums.taleworlds.com/index.php/topic,148130.0.html
an excellent armor pack for providing diversity to padded, leather, lamelar and chain mail armors:
http://forums.taleworlds.com/index.php/topic,167389.0.html
helms (I noticed you already have Deja's crusader pack in the game files, this other one has items that work better for Westeros in my opinion)
http://forums.taleworlds.com/index.php/topic,76943.0.html
more helmets
http://forums.taleworlds.com/index.php/topic,274925.0.html
and as a bonus prettier female faces (never actually tried this one though)
http://bbs.mountblade.com.cn/forum.php?mod=viewthread&tid=359343
and some lore info on weaponry in GoT
http://awoiaf.westeros.org/index.php/Armament
As a side note, you came up with some very interesting quest mechanics.
Don't remember ever encountering the faction invasion mechanic or the pre-designed battles like with the night's watch quest