Hello @GinaAsalon - for the first question, one possible approach is to create the courses and configure the settings in the courses so that students can self enroll. Then collect all the links that contain the enroll code and add them to a page in a single course and manage the enrollments in that course only. That way the Department is sure all students are enrolled to the primary course. This approach enables students to 'opt in' to all the courses set for self enrollment. See the 'View Additional Details' section toward the bottom of this page: https://community.canvaslms.com/t5/Instructor-Guide/How-do-I-set-details-for-a-course/ta-p/1037
Another approach is to configure the visibility to be 'Public' or 'Institution'. But that works only if actual enrollment isn't needed. For example, students are just accessing pages to read the content and aren't engaging in discussions, posting assignments, etc. If the latter is needed then enrollments are necessary.
Regarding theme branding, as far as I am aware, there is no effect of subaccount branding upon the dashboard. Granted, images can be added and the course naming convention may vary, but these are course level elements and are unrelated to the subaccount theme. To illustrate, below is my dashboard. The courses shown are within 4-5 different subaccounts and some of these have slightly different branding from the norm. On that note, for the most part we've found students appreciate consistency. For example, a consistent approach to using Modules, listing items on the course navigation menu in a certain way, etc. While Departments can get super creative with a theme, sometimes uniqueness can be a distraction or perhaps a hindrance.
