In my Quest mod I take the vanilla relationship system and expand upon its significance in relation to my central character. Every vanilla NPC has a relationship with the Player and those relationships vary from Enemy to Lover. Often, you achieve a relationship with an NPC by completing a Quest for them, which usually yields the reward of being able to take their things. In my mod I use this system, but the benefits of your relationship with the central character are different - they determine how much gold he will give you as a reward (if he doesn't trust you, he will give more) and whether he is willing to give you additional advice or assistance on Quests (as a friend, he will give you a potion of water-walking when you need to travel a short distance across the sea, for instance). They also offer some variations on certain Quests; for instance if he does not trust you he will give you a task that requires a bit more brute force, but if he does he will offer you a more diplomatic quest.
The way in which you affect your relationship is through your dialogue choices and your actions. If you demand payment for a task upfront you will lose trust and eventually be concerened a mercenary. If you choose to complete a Quest in a passive manner you will gain trust.
Your relationship with this character is balanced so that one (a positive relationship or a negative relationship) is not better than the other and they have no effect upon the story itself, but this still isn't something made use of to this extent in vanilla. I'm just not sure if I've made a mistake in implementing this system. I hope I haven't and I've probably left it a bit late to get an opinion on the matter, but I suppose it's better late than never. So what are your thoughts? Is this something that wouldn't bother you and something that I should keep, or something I should scrap?