Not entirely sure what you mean by "disable every other track", are you actually turning the tracks off? I would avoid that as disabling tracks outright will affect your caching.
To paste to a specific track you use the "Auto Select" tool, which is to the left of the enable/disable track button.
If you hold option/alt on the keyboard before clicking the desired track, all unwanted tracks will turn off - much like hitting the solo button in an audio application.
If there are multiple layers in your clipboard all will be pasted, starting with the lowest layer in the clipboard corr