Mike,
Absolute is considered safer for just the reason you stated: an error on a single line does not skew the whole program. Actual motor positioning errors however, behave exactly like an incremental error, no matter whether you are programming in G91 or G90.
You've got to watch your post requirements when you switch back and forth between G90 and G91. Arc coordinate format may be different in each mode.
I like absolute (G90) programming also because it can allow for mid program start at any point, with due consideration for what should have happened up to that line, of course . You can also get an idea of how to edit the program at the controller if need be, but an incremental program, well, that is nearly hopeless at the control unless you're just cutting squares or circles.
I tend to reserve incremental for creating subroutine loops, if suitable. It is difficult to switch back and forth in Bobcad. In fact, I doubt that the backplot function can properly deal with any program that has both modes in it. It may be the case that you have to switch the post driver into the proper mode before you even attempt to backplot the code in that mode. I'm uncertain of that, but that is what I would be careful of.
First you get good, then you get fast. Then grouchiness sets in.
(Note: The opinions expressed in this post are my own and are not necessarily those of CNCzone and its management)