You can of course have mix of bound and unbound forms if you add a sub_form or two but this will still probably need some coding to automate and join any relationships between forms (if required). Also, a 'bound' form can have a mix of controls of bound (to a field) and unbound (no data values) items to provide a smoother interface that would otherwise be too clumsy by design to stick with just the one type.
When you begin a company or an organization, you have to decide about its legal structure and prepare and submit legal forms. You will choose among these business types _ sole proprietorship, partnership, Limited Liability Company (LLC) or corporation. Some may also choose to function as cooperatives. There is no wrong or right choice which fits everyone; the business type suitable for one person may not be suitable for the other one. Your task is to understand in what manner each legal structure functions and then pick up the one which best fulfills your needs and requirements. To make best choice is not always easy.