Channel 0 is a sniffer channel used to test for interference. Don't use it for normal operation. Blaster is designated within CCP. Mx980 is my go to. As far as the sluggishness, RF adds some time but you can get it pretty close by using clean codes, eliminating interference and experimenting with repeats.

It's my perception that adding sounds at the beginning of the macro does not make it fire any slower but I could be wrong. You could check that but it's not enough to bother me I put ticks on all hard buttons and ugly sounds on buttons that have no purpose in a given mode.