Question on heating capacity

Hi there, homeowner here. I am trying to nail down some basics to make sure that I read different specs correctly and evaluating options/costs accordingly.

1. A GSHP system with a stated heating capacity of 50,000 Btuh at COP 4 can produce a maximum of 1,200,000 Btu if run continuously for 24 hours?

2. 1,200,000 Btu = 351,600 Watts, thus at COP 4 the system has used 351,600 / 5 = 70,320 watts or 70.3 KWatts?

3. A house with a Manual J estimate of 55,000 Btuh heat-loss will need to use the emergency heat-strip for about 10%-11% of time as at the extreme will require 55,000 X 24 = 1,320,000 Btus?

Thanks!