What you seem to want is something the Home Theater mode almost provides, but there are enough flaws in the 8910 HT mode design that you probably can't quite get it to do what you want.
With JP1 you can use a "special protocol" to dynamically change HT settings within a macro. That gets you a lot closer, but probably still not quite there.

JP1 (for the 8910) does not increase the amount o key move memory, so you still won't be able to do what you want as a large number of key moves.

The solution that almost certainly will work and fit is the "device combiner" protocol. That allows you to define new setup codes that are combinations of other setup codes. For example, you could define a VCR setup code that has the keypad functions of your cable tuner combined with transport and menu functions of your VCR.