Is everyone's heart biologically the same

Yes and no. Everyone's heart works the same way, is made of the same type of tissue and is located in the same part of the body. However, there are people with diseases who have hearts that are in worse condition and may look different. For example, people with coronary artery disease experience plaque build up in their coronary arteries, which causes a reduction of blood flow to the heart, and in order to treat this they may get a bypass surgery in which another blood vessel from somewhere else in the body, would be used to bypass the blocked blood vessel. In this case the anatomy of that person's heart would be slightly different.

Yes and no. Everyone's heart is set to work the same however some people may have different levels of health in the heart.