Yes. You actively participate in the operation of your business. DOT regulations are for certain industries and occupations that generally require you to be away from home overnight, e.g. over-the-road truck drivers, airline pilots, etc.
If you have additional questions or details regarding this, please feel free to post in the comments for further clarification.
If I only drove for 100 hours in my 3 months of driving, did I actively participate?
This response appears ambiguous, since it begins with Yes and doesn't differentiate between the two questions. To clarify, wouldn't the following be true:
Yes: Actively participates
No: Not subject to DOT service limits
It depends which city you are driving. Uber has its own company wide policy of partners not driving for more than 12 hours a day. However, some cities have more stringent work conditions for which Uber will have to comply. So, it depends on where you are registered to drive.