Thats why medical tests are there ..isn't it? If the medical test doesn't flag anything . There is no Misinterpretation.
Where in the Express Entry/PR profile they ask do you have any medical issues which cannot be detected via Medical test??
There is no Grace period; that used to be before the CA-IND situation. Also travel plan is a valid reason for Oath Re-Scheduling. Many have done this already.
Even if you don't have the SC in hand but if you have the receipt of SC showing that you have already applied for SC; the receipt will work for Entry visa.
Even if you don't have the SC in hand but if you have the receipt of SC showing that you have already applied for SC; the receipt will work for Entry visa.