Great feedback! We appreciate the time you put into your post.
And as you have guessed most of these issues are related - they are pathfinding system issues. In fact we are working on a brand new pathfinding system that will not only resolve issues you have mentioned but make unit behavior much much better - which will greatly help in PvP battles.
Welcome to DoF - and hope the WIP status of some pathfinding and GUI elements doesn`t scare off - we hope to have all of this fixed in the next several weeks.