Multiple apps within a package with same code base in different names, icons, logos and scheme

We are a software company and have clinic appointment and management app that will offer it to clinics; each clinic will have a license with the same source code/codebase but in different name, logo, icon, contacts and schemes depending on their details. So, 1. Can we submit the same app codebase with different names, logo, icon and colors under one developer account? Or should we buy account for each clinic? 2. If yes, How can we add them under one project to submit updates or fix bugs at once? because there will be many multiple apps and it will waste time to update one by one. 3. Is there limited number of apps? Because we will add more than 100 clinics apps. Thanks.