Getting extra blank minutes at the end of the video
There are three things you have to get right:


You have to have the right length of video in your sequence (which can be helped by having explicitly set in and out markers at the right place).
You have to export the correct sequence.  If you don't have the correct sequence selected when you render, your export might, by coincidence, render the same content you are looking at, but from from a differently defined perspective--one that has a different concept of the in and out points you have defined for the sequence you should be rendering.
In the rendering window, there are several options, including whether to render the whole clip (irrespective of in and out points), render just between in and out, or some other options.


Try setting the correct in and out points, rendering the correct sequence, and then ensuring that your rendering actually honors the sequence's in and out points.