Burning at the lowest supported speed is a persistent myth. The speed you burn at depends on how well your burner/firmware gets on with that media.
Generally, I tend to burn 8x media at 8x, and 16x media at 8x or 12x - this is my personal preference, and I rarely get coasters or playback problems.
Most burners will support TY very nicely. I find the LiteOn burners I've had have burned -R better than the other burners I have, but others have reported LiteOn preferring +R, so I guess I could be in the minority there.
As for software, I've never done what you're planning, so I can't help there.