1) maybe try these values for the lightShape: 40/1/8. using a high sample limit of more than 1 or 2 most often makes no sense in my opinion in terms of quality/performance. but make sure to up the low samples to at least 4 or more.

2) you didn´t turn on FG. all the samples are kind of "RAW" in this rendering, means there happens no interpolation through final gathering. unless you crank up photons/areaLight samples to ridiculous high values you won´t get smooth results. for testing try FG settings: Accuracy 50 and point density 0,1.