The frame bump is the smallest increment. However, by expanding the timeline via the slider (bottom-right), precision can be improved.

As for those 'parts' - let's take a look. Upload a sample project for analysis, per the instructions in your other thread. Use the edge buttons for insertions to ensure that the edit is being made at the junction.
To see gaps or fragments on track one, switch to Storyboard mode. 
Did you test the latest version?