I haven't played Fable II before but it would add in much fun and adventurous. It would give you something to do. I'm sick of tired of looking around and slaughtering people; it gets boring after a while.
Yeah, you have to 'nurture' your relationships by visiting and interacting with your spouse(s) (yeah, you can have multiples - I recommend only 1 per zone though

). It gives you something to do other than kill stuff.

Not necessary. If you play a female character, and if you have six most likely you will get pregnant, since I don't believe theirs such device like a condem that is in existence in skyrim.
They have condems in Fable.

...and the STDs in Fable are incurable.
