The default plank is sliced because once placed the evenly planks, the remaining gap doesn't fit with an exact number of default segments. So, the only way to fit is slicing them. Really is not the next plank after the evenly, but just before it (spline is clockwise oriented).
You can adjust the evenly distance to avoid this issue, or use an alternative construction mode, i.e. a sequence of 14 x default planks + A + B + C. Obviously, in this case the evenly features (as "Justify") will not be available.
There is not hole before the corner, because "Adjust to End" is set to 100% for this generator. This parameter is described
here.
Note: before computing the evenly positions, the spline is divided in "sections", and the evenly sequence is adjusted for that section. A section is the portion of path between two vertices. If the evenly rule doesn't work as expected, check if there are extra vertices in the spline. You also can change Generator->Corner->Vertex Type to modify this behaviour. We have plans to change slightly this functionality.