To answer your questions:
1) I have an existing default sidebar that appears on most pages. Customize sidebar was only meant for one of the pages in the website.
2) After checking the page that needs the customize sidebar, i went on to widgets to add the necessary links. I tried both ways which is adding and not replacing as well as replacing the entire side bar, both did not work.
My apologise because i will not be doing any more testing, my client wanted it asap. So i had replaced with another plugin.
Thanks Eric for responding though.