First thing's first... congrats!
I paid 100% for our wedding, and that avoided the kind of haggling over guests, protocol and ettiquette that you described. We got to plan the day exactly how WE wanted it, which was casual and relaxed. "No ties allowed, but please bring your dogs." Mind you, we had an outdoor wedding at my wife's family cottage, so that kept costs really low and allowed us to splurge on liquor & food.
Before we told people we were getting married, we planned the whole ceremony... right down to appetizers and who stands where when. That way when people started innundating us with "oh you need to do such and such like so and so did at their wedding" we just said, "Thanks for the suggestion, but it's already been planned".
By keeping it small and manageable we really enjoyed the whole day, as well as the planning.
