@Lee5885 A few answers:
Yes you can edit anything once you go live. In fact once live you get far more amenities to choose from etc.
To correct your listing you need 4 individual listings each for 1 bedroom and 1 person. You can duplicate the listing to achieve this but many things will default to what Airbnb wants so you must edit it carefully once duplicated.
Finally go to your account and switch on pro tools. This gives access to a multi calendar that is essential for managing 4 listings. It also gives you rulesets so you can vary some things by time of year.
Hope this helps