Your other relationships in the game come from your family, if you choose to have one. By using gestures (the game's means to interact with others, in socially acceptable ways or not) you're able to woo the love of your life, move into your marital home (you can also buy property to rent if you like), start a family and then pay an allowance for house upkeep for the rest of your life. You won't see your family nearly as much as you see your dog, so the relationship isn't nearly as strong - or at least it wasn't for us. You can instantly teleport back to your home at any time (something you can do for more or less all the main locations in the game), so you can visit as often as you like. You can dish out affection and hand over gifts (be careful not to give your wife a pauper's ring or she'll likely divorce you), and see your children grow up, so that relationship can really be as strong as you want it to be. For us it played second fiddle to the main quest, but each to their own.
As far as RPGs go Fable II is remarkably streamlined, and devoid of many of the barriers to entry you'd usually associate with games from the genre. You can upgrade your character using experience orbs (in Strength, Abilities and Will - magic by another name), acquire new weapons and clothing, and stock up on potions and food, but you'll never get bogged down with the inventory or your character's stats. In fact, if you're unhappy with a route you've taken you can remove an upgrade and use the points elsewhere.
This isn't to say that character development is poor by any means. Your hero will truly be your own creation by the end of the game, shaped by choices, corrupt or pure by your actions, rich or poor, loved or loveless. He'll look unique, be adept at a certain set of skills and perhaps even run a business or two. You'll just never have to spend ages routing around in an inventory screen. The game does a good job at offering you instantly selectable items or commands on the d-pad, deciding what to show you depending on the situation. If you're low on health a health potion will appear on a direction, whereas if you're close to your dog you'll be able to access all the interaction gestures at the touch of a button.
Fable II is a game that almost anyone could play through. It's not hard in the traditional sense, with combat being as simple as it can be (repeatedly pressing a single button suffices for the most part, either in melee or ranged combat). Death is something that we didn't have to contend with, with our inventory always stocked with enough potions to keep us from falling in battle. It helps that your magic can be upgraded to incredibly powerful spells of destruction, able to wipe out swarms of enemies in a single charged spell. Towards the end of the game, after working to upgrade a few choice spells, armed with a Master weapon and the strength of a bear, a hero had truly been born.
Some may see the combat as overly simplistic, but it proves to be entertaining and fit for purpose. A game about a hero that struggles to overcome insignificant enemies isn't what Fable II is about. Lionhead wants everyone to be able to experience a game about choices, with decisions being the main difficulty you'll encounter. This they've achieved, with almost every quest or event offering you more than a single, clear-cut choice. It's not as open-ended as it could be, but it's far beyond a single branching path that splits the story at some arbitrary point in the game.