Push karma primarily affects how likely the release engineering team will accept any breaking of the standard rules of getting your code into the push. It generally doesn't drop if you are responsive and responsible for any problems your change causes. The only way to restore points is to show respect and consideration for the hard work the release engineering team does.
(I'm not 100% sure, but I think most of the booze and cupcakes come from people who were appreciative of the release engineering team for bringing potential issues to their attention or for being accommodating in terms of hours and in terms of delay to get things fixed.)
Being irresponsible (not supporting your changes) will factor into your performance review, but working exclusively on low-risk features will most likely hurt it way more.
(I'm not 100% sure, but I think most of the booze and cupcakes come from people who were appreciative of the release engineering team for bringing potential issues to their attention or for being accommodating in terms of hours and in terms of delay to get things fixed.)
Being irresponsible (not supporting your changes) will factor into your performance review, but working exclusively on low-risk features will most likely hurt it way more.