I kept this model for 5 years and went to Murree, Bhurbhan, Nathia Gali and "Abottabad via Bhurbhan". Though it's engine is a bit less powered but I drove on last route with 4 passengers (including my self) and came back to bhurbhan side and issues 1, 2 and 3 were not faced. However, I am assuming that one knows how to drive in hilly areas and this goes for any car, you have to change gears when more power is needed or overtaking and in addition to brake you drive in low gear downhill so that brake is used alternatively with gear.
However, pillars issue is there as on some occasions I felt that pillars were too wide. This could be a problem when you have sharp turns. However, I knew it and drove accordingly and faced no issues as such.