To an extent, yes. That is basically what a mastering engineer does.. they are editing a 2 track file.
You're basically limited to how well the YouTube beat was mixed. The biggest problem will be if the file was over compresses/limited or distorted in a bad way.
Most of the time when I've mixed a 2 track beat, I end up expanding it bc it was over compressed. Then I add or remove some bass if needed with an eq or multiband compressor and do the same for the highs.
To get the vocals sitting nicely I'll usually use a mid/side eq or compressor and turn down the midrange in the center only, thatshould make some room for the vocal to be heard. Although a better way to do that is by using a multiband compressor and sidechain it to the vocal so that anytime the vocal is on, it ducks out some of the midrange in the center only. This is often better than eq because it keeps the midrange in the beat when the vocal isn't on
