Please refer to this earlier comment. It should answer your first question. comments.deviantart.com/1/4863…
For question 2, genre colors is currently not supported by the Spotify plugin. Keep in mind that this portion of the plugin is still in Beta and that this functionality will likely be added in future versions of Rainmeter.
For question 3, I assume you mean that there are two or three lines on the bass end that are consistently at 100% when playing music. There are a couple ways of fixing this:
1. Modify your frequency range (mine is 40-16000)
2. Turn down the output volume of the program it is feeding from or lower the sensitivity (My sensitivity setting is at 30).
The sensitivity setting can be found in variables.ini (right click on the skin, edit settings). The FreqMin and FreqMax can be found in the settings for the visualizer portion of the skin. For myself, I've adjusted both of these configurations, but what you do depends on a multitude of variables, including what kind of music you're listening to and its volume.