It may have been in his document, but I agree. ALWAYS list make and model of the equipment you are talking about.
If your TV has it, while ARC may work, you may have more consistent results by using a digital optical output from the TV to your A/V receiver.
Depending on the make/model of your receiver, you could hook the cable box up to your receiver, and while the receiver is powered off, it may be able to pass audio and video to the TV from the cable box automatically. Some do that, others do not.
ARC may work just fine, but it can also be buggy from some people at times.
At the end of the day, your TV speakers are crap and you are saying that you really want to do some 'crap' listening most of the time, and only use the top-dollar good stuff from time-to-time. You can see how this makes very little sense when worded as such. If you get a good remote, you can listen to your good speakers all of the time and it should be just as easy as using the TV speakers. One button to turn it on, and the volume up/down goes with the A/V receiver. But, it depends on what you have. Makes no sense to use lousy speakers when you have good speakers though.