This is a very new ship and they are so precious.

who throws things in a fight ?
They don't fight very often- the only time I can think when they fought was when they were chained together at the start. In which case Neirion was more likely to throw stuff. Like y'know... punches.

who goes to their parent's house for a weekend when things get bad ?
Neither of them have parents... oops.

who wants to have children ? who doesn't ? if both do, how do their goals differentiate ?
They certainly haven't even thought of having kids. They want to move to Gondor and have a garden first. Their children will be their plants and trees.

who is more adverse to physical contact ?
Alcarin. He's been very badly abused in the past and as a result has a discomfort about people physically touching him. He's getting better- but he hates healers examining him and only cuddles Neirion.

who hates/dislikes their neighbors the most ?
Neirion. He's a grumpy little baby who doesn't like strangers or neighbours much. They don't really have neighbours at the moment, just elves in Lorien milling about.

who hates/dislikes their significant other's family ?
This is an interesting one- Alcarin and Neirion haven't met their families yet. For Alcarin, he will hate Cainir, Neirion's father because he was stuck tied up in a room above where Cainir tortured people. The screams of the victims used to frighten him and even hearing screaming now triggers a panic attack because he's secretly paranoid he's going to lose the freedom and love he's found in Neirion, that one day he'll open his eyes and be in the dark, restrained again. Neirion already dislikes his own father and doesn't have a great impression of Alcarin's parents because as far as it's known, they abandoned their infant son and left him with an abusive 'master' as Alcarin calls Mordin.

who is most likely to leave when things get rough?
Neither would leave because they both have a fear of being alone. They've already been through a very rough patch (cue the montage of the fighting, Alcarin getting his ribs broken, the crying, the shouting, the dragging etc)

who thinks their partner turned out a different person than they thought ?
Neirion. 100% Neirion. His opinion on Alcarin as a person has changed so dramatically.  At first he thought Alcarin was insane and deserved to be put in a cushioned room for the rest of his life, he was quite set on the thought that Alcarin was evil and clinically insane. After hearing him cry for the first time, he suddenly realised that Alcarin wasn't any of those things, that he wasn't insane, just a very frightened, upset little elf who'd been through years and years of abuse and that he didn't need healers giving him all sorts of medicines and checkups, instead that Alcarin needed sunlight, some gentle love and attention and a lot of patience. (As well as a reeducation about what was acceptable in a relationship because he was convinced physical violence was okay)

who is more likely to cheat ?
Probably Alcarin but unintentionally. He isn't unused to people asking him for sexual favours- most of the time not asking. Due to his experiences, doing as he's told is a natural reflex, and if someone asks him for something unsavoury, he obliges even if it upsets him. But Neirion is teaching him that that's wrong and that he doesn't have to that anymore.

who is the more experienced ( sexually or otherwise ) ?
Neirion is more experienced in healthy relationships and that sort of thing, sexually would be difficult to say, because while both Neirion and Alcarin have experience in that area- Neirion's wasn't forced on him the way Alcarin's was. Neither of them are virgins but I'd say Neirion has more experienced in experiences in general because he's reteaching Alcarin right from wrong and all Alcarins experiences came from abusive relationships.

who hates/dislikes their significant other's friends.
What friends?

who wants to go to social gatherings the most ?
Neither of them. Neirion hates peoples and Alcarin has social anxieties. Neither of them like socialising.

who is most likely to be dishonest ?
Either of them could lie, Alcarin would because he was raised in an environment where lying was common and considered normal and right. Neirion would lie because he didn't want to worry or upset Alcarin. Or anyone for that matter.

who is more emotionally closed off and how does this affect their partner ?
Alcarin I'd say. Because of his past and his upbringing- he realised hiding his emotions and crushing them made everything he had to do and everything that was done to him seem easier. Especially while he was beaten by Mordin or used by Aegon. Feeling nothing made it so much easier.  To begin with, Neirion was a little annoyed by Alcarin's lack of response the times he attempted communication, but after a while of gradually learning little bits about Alcarin's past, he softened a lot and doesn't mind now. Alcarin shows more emotions now, he feels safe enough to do so but that's down to Neirion's gentle and loving care.

who is the dessert person ?
Alcarin, he loves sweet foods like berries, honey and such. He never had them much growing up so having them now makes up for it.

who is more conservative ?
There is nothing traditional or conservative about them. They don't have any traditions from their cultures as Neirion only just learnt about his and Alcarin didn't grow up in his culture he grew up in Mordins which was worship of Melkor- god of chaos and darkness.

who hates/dislikes oral sex ?
Alcarin doesn't like being touched like that at the moment, it brings back too many nasty memories that he would rather forget. He doesn't like giving it either- he was always forced into it before and would always end up choking or gagging and he'd feel like he was suffocating.

Ru-Feä however (Alcarin's second personality initially created to deal with things that scared him as a child) loved both giving and receiving until he was ripped from Alcarin's mind and put in a locket with a spell on it to contain him.