Can leaky heart valves cause blood pooling in legs and hands? many thanks?

Yes, when the valve is leaking too much (severe regurgitation, either mitral valve or aortic valve) you can develop congestive heart failure then there is not enough blood flow to the kidneys so the kidneys will retain salt and water and the end result will be body swelling, first with the legs and then to the arms and trunk if significant fluid retention occurs.