Q3 modifs:

The biggest assumption we made for this model was that people are at their maximum midiflorian value when infected, and production of midiflorian is halted indefinitely. We could modify the model such that people aren't always at their maximum when infected. In this case, this person still succumbs to the virus, as shown by a special case of question 4 [when q = 0 in case 2]. Other possible modifications would be to allow a time delay between infection and destruction of midiflorians, and for extra virus to enter the body after initial infection.

Q4 modifs:

Similar to the virus modifications in question 3, we could add a time delay and/or hunting time for the anti-viral killing the virus. A more significant modification would be to consider the change in effectiveness of the anti-viral over time by making q a function of time.