In this specific model i think that both solutions would be correct. The no-bend option is suitable for 90 degree corners, but for other angles a bended piece would fit better, as shown in the image.
To get a square corner, you can make the following changes:
- Turn off Bend for the Corner segment
- Set Geometry->Corner Rule->Fillet to 0º
- Uncheck Geometry->Corner Rule->Align to Path
It is not necessary to make these changes every time. You can create a custom model, and save it in the Library. The procedure is described here:
http://www.itoosoft.com/railclone2/reference/library_editor.php (in this case for RC2, but the procedure is the same)
About the endpoint issue, this is caused because the corner piece is used also for the Start and End rules, and its Pivot is centered. In RC2 this problem may be easily solved, setting the Alignment in the X axis to "Automatic". For RC1, would be necessary to create separated segments for Start/End, using different alignments.