Correct procedures are put in place for safe conduct of flight full stop...breaching them can increase the risk of a safe conducted flight and I believe if you feel out of place with what is happening express your concern to the Captain and let him know you are concerned with the way he or she has proceeded with the approach (in your case the speed below 10000ft and the correct approach pattern) etc...
I believe there is no harm in speaking up. Advise the Captain of the correct speed in your case 210kts for the procedure and not 280kt.. Get you point through until you are satisfied with the result between Captain and F/O …but then again I can imagine the situation you are in and along with the many RHS pilots who go through it…