I visited a lot (DH and I dated for seven years, to my poor mother's disgrace). I was asked to present a letter from my employer once, but I always, always, always had a return ticket, enough money (if they asked), and a flat/job to go home to.
The IOs were actually, on the whole, really nice to me. I'd tell them I was visiting my British boyfriend/fiancé/husband (as the years went on!), and I never had any trouble. I always had a job and home to go back to--the only time I had ANY trouble was when I went on holiday with DH (then boyfriend) to France and the woman at Stansted gave me a minor grilling as I think SHE thought I was trying to restart the 6 month visa. Otherwise, even when we were already married, honestly it was no trouble.
I don't think you need the names and numbers of everyone you're visiting, they are more interested in you proving that a) you know the rules and can support yourself while here and b) you are planning on LEAVING.
Have fun!