Send written invitations or emails.  Give out the "house rules'.  This can be done in a light handed manner such as  'please, no helping in the kitchen, I have everything organized and if you help, chances are that I will lose track of what I am doing and we will all have to go to MacDonalds as dinner will be a disaster.  I appreciate your good intentions but just bring your appetite and not helping hands'.
Other problems can be covered in a similar manner.  If people take umbrage, this will weed out the individuals who spoil the get-together for others.  With any luck, you will end up with fewer people and have a much nicer time.