Are all lymph nodes in the groin area, what most doctors call benign tumors, felt by lightly pressing the area?

No: lymph nodes eare found around major venous structures that drain important body parts. The groin nodes along femoral vein drain leg and perineum. Nodes in axilla drain upper extremities and breast. Nodes in neck drain oral cavity. When felt in groin and clustered , they must be watched for increase in number and size with bx considered if such happens to assure neoplasm not rsponsible.

No, and no: Lymph nodes are not tumors. An enlarged lymph node is not a benign tumor, though because there are no benign tumors of the lymphatic system, we may call it "benign". The vast majority of groin lymph nodes are not palpable. When I was a barefoot-summers kid, I got big groin nodes whenever it was nice out. Life's to hard already to worry about each lymph node that comes up. Relax.