Blood pressure is not a problem at all.
A1: It will only impact the exams if the blood pressure has been uncontrolled (or badly controlled) for a few years generating a damage in the kidneys, which will make the
Creatinine go up. If that's the case and your father already knows the Creatinine is going to be high on the blood test, then your father's doctor should already be aware and before getting the medicals, you should get a report (in
English or French) from your father's Nephrologist indicating that his condition is stable and he won't need extreme measures to maintain his stability. This report is attached to the Emedical report sent to IRCC by the panel physician
(sorry if I'm too technical)
A2: of course he should take his medicine, there's no need to be fasting when doing the medicals
A3: sorry no answer for that