Is to much sex bad for your heart?

Too much? Hard to know how much is "too much". The normal increase in heart rate with sexual arousal is not dangerous. If you already have heart disease or get chest pains with sexual activity get evaluated by your doctor.
Not that we know of. The only time when sex can be harmful to the heart is if it brings on chest pain or severe shortness of breath, otherwise, it is good indicator of healthy cardiovascular system.
Not usually. In a healthy person without heart disease, sex even frequently does contribute to heart disease. If a person has significant heart disease or risk factors for coronary artery disease, any stressful event or strenuous exercise such as sexual activity may precipitate a heart attack.
No. No, unless you're getting chest pains or shortness of breath, or palpitations with it , your heart just sees it as exercise, like walking up two flights of stairs( if not a new partner).