first : english is not my first langage - but i will try to make me understand

i have one question and one problem :
1. question : is it possible to make vary the volume of a track inside it ? i mean, in other sofware like Mixcraft, Adobe Audition etc ... you can manipulate "handles" inside the track and vary the volume + or - on different sections. I tryed it in MTD by cutting the track but the big round handles only can be used to fade in or out. or do i miss something ?
2. Problem : when i listen to a finalised (and mastered) outputted song the volume is always the same. that means that if there is only one instrument playing his volume is very hard and "overdriven"

you can hear it here in the third part of the song (+/- 3min.) : http://jacq.bandcamp.com/track/struggle
thank you for the answers
otherwise, this is a very nice app
