Lena is gone again. She was Buck´s temporary replacement, he is back, so she is presumably back at her old station the 133 I think?
The line from Eddie you didn´t understand was "you are at 100%, the lawsuit proved that, right?" so he was a bit passive aggressive. Just like when he immediately said "It´s none of your business" to Buck when he asked about Chris allegedly roughing up Eddie like that.
About the calls being a bit "unrealistic" some might be a bit exaggerated, but I´m pretty sure most, if not all of them, are based on actual 911 calls. Crazy stuff just happens. In a TV show the frequency of crazy is just ramped up.
They wrapped up the whole lawsuit/Bobby being mad at Buck stuff really fast, maybe a bit too fast, but I´m kinda glad we aren´t dragging this out for too long and get back to relative normalcy with the team.