1. I don't understand why people are so against in-game relationships with NPCs, that may include physical relationships. So long as the game isn't focused around them, more likely than not, they'd be completely optional.
Some games just push the whole relationship thing, like 4,000 kids running around a cramped house with a partner that constantly demands gifts, or leaves. However, having a companion that will scream and/or cries when you die, will have more unique dialogue than all of the others, and will follow you around loyally, unless your disposition drops below a certain point.
However, I don't expect Bethesda to make a game based on relationships like some other games, TES:V could work fine with relationships, so long as they weren't 110% part of the story. That extra 10% is how you can do 4000 things to make a character do something you never expected and completely change the story's outcome.
First, we must establish that there is no such thing as "completely optional" when talking about something whose inclusion ends up eating a lot of resources. For the person who doesn't want a mechanic and will never use that mechanic, they don't get an even trade-off by deciding not to use it. By the inclusion of an option they find worthless, they've lost resources that might have gone to other mechanics they do like instead.
I wish that some of the marriage threads had survived the forum culling, because I had a nice log gigantopost about why relationships as presented by video games are only worth the inclusion if they are believable, and the criteria I hold for "believable" is simply too strong for Bethesda to implement without svcking the rest of the game dry for resources.
For example,
1) Restriction of relationship choice is not believable. Being presented with a handful of relationship presets in a world with 800+ people is artificial and fake and immersion-breaking. If I am to have relationships, then it should be my choice whom I establish a relationship with.
2) Courting processes must have realistic potential length. While some NPCs might run after the player after a week's worth of actions, the process should have a maximum threshold of 2 months of constant fresh courting activity. Having anyone you want fall for you in a uniformly short time period is artificial and fake and immersion-breaking.
3) Courting itself should be significantly more complex than "Here's a gift, coupled with some dialogue options. Now fall for me." As mentioned above, courting should be reminiscent of the Ahnassi questline in Morrowind, where you slowly work your way into a person's life via a string of occurrences and actions. Having simplified courting procedures is artificial and fake and immersion-breaking.
4) Dialogue for NPCs in all stages of relationships should be different. If I have a falling out with NPC [X] and find sparks with NPC [Y] instead, I don't want them to go through the same dialogue. Repetition of dialogue is artificial and fake and immersion-breaking.
Now, keep (1) in mind when considering (2), (3), and (4), meaning that all the specifications in the latter numbers would have to be multiplied by at least half of the NPCs present in the game in order to satisfy "believable" criteria.
Simple condensing of the argument: I have never played a game (including DA:O and the rest of Bioware's stuff) that does relationship's convincingly. And if they're not done convincingly, I have no desire to see Bethesda use resources on something I'd never use.