Why do you hate the usage of parenthesis' so much? To me it sounds very biased to judge a mod so hard based on writing techniques. Like the very use of parenthesis is a reason to dislike a mod. I for one don't think descriptive story telling in itself is a bad thing. In fact, if anything can set the admosphere in a mod, it's the use of descriptive writing, as long as theres a balance between actual dialogue and parenthesis'.
*Ack, two posts before I could even respond to your first one gert.
I'm not docking mods on there writing techniques per say, I'm docking them on their presentation of characters/themes/ideas. What is the point of developing a mod if you don't use the strengths of the gaming medium to express the personality of your characters? If a mod uses parenthesis more than dialogue/voice or in-game actions why don't they just write a piece of fanfic or a book about their character and stick a portrait on for a cover/heading. What modding or developing games allows you to do is present such things as characters and events in a way that is largely different, and maybe even superior, to books and movies.
When an author/team settles on a parenthetical rather than in-game or voiced dialogue approach they are completely missing the point of developing a character through the game. The absolute best example of this is an instance in the Kivan mod. (1) Kivan's racial enemy is Ogres, and when you go to Umar Hills and have to negotiate with Maduf, (2) Kivan suggests that you should attack them on sight. (3) If you talk to Maduf anyway Kivan "tenses up" or so we told from the dialogue box, but no actual dialogue is spoken between any characters. (4) After you successfully negotiate with Maduf, Kivan tells you that he was wrong and that you showed good judgement.
So let's take a look at that event step by step.
(1) Kivan's racial enemy being Ogre is simply part of the game system.

(2) The author has done an excellent job of using part of the game system (Kivan's racial enemy) to extrapolate a reasonable reaction he would have toward Maduf. Excellent work!

(3) A parenthetical is used here to describe Kivan and show how much he is stressed. The parenthetical utilizes the dialogue box but there is no spoken dialogue between characters.

(4) Kivan respects the main character's decision and tells him so in dialogue.

Steps 1,2,4 are all fine and use the game system well enough. I especially like how the author's inclusion of Kivan's reaction based on his racial enemy. But what about step 3? Not only does it make Kivan stick out compared to his companions (the Bioware NPCs) it really doesn't give us anything that we could have extrapolated from a better written step 2 or 4. Let's think of all the ways we could have replaced or modified step 3 in the aforementioned event.
A. We could have skipped 3 entirely and had Kivan tell the main character he was tensed up the entire scene as part of step 4.
B. We could have had Kivan interrupt and trade words with Maduf, but ultimately have Maduf appeal to the main character. That would ensure that Kivan's reaction is seen but still leave the choice of the player of what action to take.
C. We could have had an in-game cut scene (or scripted event) before, during, or after the dialogue where Kivan shoots the dirty Ogre anyway. This takes away player choice but is more likely to garner a reaction from the player and he/she will probably remember the event.
D. We could have had another member to tell Kivan to relax or lower his weapon. This gives more of a party/group atmosphere while still showing the scene is tense.
All of these keep Kivan from being too different from other NPCs and thus killing the mood of the moment but also get the same idea across that the author originally intended. Options A,B,D would require very little more effort to code/script and option C would have made me wary of placing Kivan near any Ogres in the future and been a highlight point of the mod. Instead I know remember that specific encounter for not being completely awesome but for being a lame, missed opportunity to do something cool.
The Yasraena mod is even worse. It has some really terrible moments in it where entire dialogue sequences are just Yasraena doing random crap - not even interacting with other characters. As much as I wanted to enjoy that mod it just wasn't up to snuff. She wasn't a very interesting, consistent, or compelling character. Part of the reason is that she doesn't actually say or do anything much memorable. All the god damn text is lame descriptions. I mean I kept her in my party for >20 hours. I can't remember a damn thing she did or said besides ask what gems meant on the surface. I replied that rubies are for passion, and then I checked to see what was on her necklace, which just happened to be a ruby. When that is the only thing I can remember about your character after having spent 20 hours playing her you have serious presentation problems. Shit, I remember more about Keto from her intro in the Five Flagons Inn. She freaking ran away from a bunch of kobolds in the Firewine Ruins, and she like to rag on the dwarf with the inferiority complex. And guess what, I've never even had Keto in my party, I just passed by her doing some lame fed-ex quest for the character I cared less about, Yasraena. At that point I was like, man, Yas is such a crappy character -- So I dropped her from the party, hoping she'd fail her quest to find her nancy Elf lover; and then I picked up a real character -- Keldorn, who is one of those self righetous bastards that I hate, but still is 5 times more memorable than Yasraena.
A few mods can get away with the parentheticals, particularly the Flirtpack-esque stuff, since it's basically all completely new material that is consistent for all the characters (that have romances anyway). But as soon as you start using parentheticals for basic actions/reactions that are non romance related and can be easily accomplished with normal dialogue I believe you are killing the quality of your mod.