Hi,
My guess is that the additional large posts are at the end of the spline rather than the beginning. The sequence operator is a simple counter so it's just progresses through the segments and stops at an arbitrary point based on the length of the spline. Another option might be to change the Evenly Mode to Count and export the value using a Numeric node. In that way, you could control the number of Evenly divisions and adjust it so that the start and end match.
As for deformation, you could turn off the Bend option for the posts, but you'd probably need to structure the graph a little differently, perhaps adding the top handrail to a separate generator so that it can continue to smoothly bend and follow the curve.
Best,
Paul