1) Yes, it's possible to disable the possibility to edit the posts or pages for the regular users (owners). For having this feature you are need to create these WordPress users as a subscribers. So such type of users can not edit or publish the posts. But please note, you will be need to insert the booking shortcodes (insertion form) manually, when you are logged in as super booking admin, but create the booking resources for the specific user you can only if you or your user is logged in as specific user (regular user/owner).
Also, when you are login as super booking admin you are need to set the appropriate user role (subscriber) for the each booking admin menu pages, you can make it at the general booking settings page (at the right side of the page).
2) By default this version is not support integration of payment form for the only one single PayPal account, each WordPress user can customize and Activate own parent account.
But it's possible to customize this version to have available only one PayPal account for the any users. Please contact the support about it, at the support section of plugin site.