for your first problem, most electronic equipment today have multiple audio outputs. example: a dvd player has analog, coaxcial digital, spdif fiber optic and 5.1 ch output. You can run the analog left and right to your tv, and spdif digital to you preamp. samething with directv or dishnetwork etc.. that way if you want to use your av system, just bring the tv's volume all the way down.

personally, I use my dvd player as an SACD player, dvd player, Cd player and directly to my tv also. So I use the HDMI connection to my TV that also caries audio, spdif out from the dvd to dvd in, coaxial out to cd in and 5.1 ch to the 7.1 input for SACDs.

For your second problem, the tv has 8 inputs plus the tuner. Turn off all the ones that you are not useing. Set them to skip, That way you will have to press the tv/video button less.