1) Namaz in jamaat has precedence
2) Take part in congregational prayers and prior to that if you can recite even two rakaat nawafil, then do so and complete the rest later.
3) The namaz is counted as being recited awwal e waqt
4) However much namaz one recites, she/he is rewarded. The statement, that one should not do more than 51 units even if they can, maybe for individuals. A thing being makrooh means less reward. Sometimes a person prays a lot and then completely gets put off Namaz.