There's nothing wrong with using branching, except (as you have found) it will mean that your slide count will look a bit odd.
The link you included above explains a way to organise the slide numbering via variables and that would be the way I would suggest you did it as well.
I have set it up and got it working. I did need to setup the On Entry action for each slide to callup the Advanced Action. Is this correct? Doesn't this limit the use of future advanced actions in my course?
Is there a way to get the Advanced Action to run in the background of all the slides?
You can still use the same event to trigger more than one Advanced Action.
You just need to add the other Advanced Actions on separate lines in the AA dialog.
In most courses there aren't usually a lot of Advanced Actions triggered via OnSlideEnter for every slide. So I would recommend you have a default SlideEntryFunctions Conditional Advanced Action and use this repeatedly on each slide. Just add items to this as separately named actions. This gives you the freedom to change one without bothering the others, and it also means you can test for more than one condition. If you want the Conditional Action to function more or less like a standard action, just use If 1=1 as your Condition. It will always be true and the action will get executed regardless.
Thanks for the reply Ron