All websites in the multisite are independent and have own database tables, and they can have own plugins and own post types.
Hi, i’m glad you figured out the registration process. In a future update we will have default registration fields.
If ACF (or any other plugin) is active on the site you do not need to include its files as they are all being included in the wordpress initialization process. The only tricky part is that you don’t know the order in which files are included and yours might be included before the ACF files are included, therefor you should probably wait for the init action or even later action before using it.
