In any swimming event that isn't a fin, is there a particular stroke that is required? Will I be able to use CSS on the non finning swims?
When you have fins on you will do the Combat recovery stroke or lead arm trail arm swim. Without fins on, you will do freestyle unless you’re dragging a buddy or swimming underwater.
For the 500m PAST swim are we allowed to do a combat side stroke or only freestyle?
You are allowed to do any stroke you want. But it is highly recommended you use free style.