So I’ve spotted my cues and placed the necessary markers. I’ve moved around the bars with the time warp and that has automatically created tempo map with the necessary tempo jumps.
Now I’ve placed some additional markers and want to create further tempo changes BUT I don’t want the music later to get disturbed and fall out of place with the video. How do I accomplish this? I realize its a newbie question so please bear with me. 
I’m watching this closely for responses. I’ve got what may be a similar question problem ( Re-recording part in a variable-tempo project: Grid - Cubase - Steinberg Forums ) that I’m losing my mind over. Is there no other way to redo a section in the middle of a variable tempo project without being forced to manually realign all the subsequent tempo points?
To the OP, I figured out a way to make tempo changes inside a project without later tempo changes having to be all out of whack. I detailed it in the post I linked to a few posts up, but briefly it involves putting all the tracks in linear time base, and splitting the project at the time point the changes will be made. I hope that is helpful in your situation as well.
Best wishes -