Hi there, Faheem Bial.
I appreciate the detailed information you've provided regarding your concerns today. With your first question, QuickBooks has different types of users and the level of permissions to access your company. For more details, you can check our user types and user permissions in QuickBooks Online that contain the different levels of access to what a user can do and can't do.
On the other hand, we can only add up to 25 users only for Advanced. Adding another user is unavailable yet. For now, we can take this as a product suggestion, and who knows, this may be added in future product enhancement. You can check out our QuickBooks Blog to stay updated with the latest features of our product.
Lastly, the option of consolidating reports from both companies is unavailable in QBO. You may consider looking for a third-party application that can help you accomplish the task. Please visit our App Center for the lists of apps.
If you have other concerns, please don't hesitate to get back to us.