You will be lifting. You aren’t going to be be picking people up out of a chair (though you will have to help them stand up). A head alone weighs about 12 pounds. A leg is heavy. You will have to help someone get on a stationary bike, or similar. So yes, lifting is needed.
If you are a physical therapist, a large percentage of your clients will be elderly. Yes, it is likely you will encounter the loss of a patient at some point. I’m not sure if you mean will you be present when that happens though.