macOS X: Simple mouse key macros and keyboard remapping

Before I moved to Mac, I used to have a specific set up with my two side buttons on my mouse. I would like to have that now as well. Ideally I would like to see it get done in Hammerspoon ([login to view URL], based on Lua), but am open to other options as well. First, there are 5 buttons: Button 1 - Left click Button 2 - Right click Button 3 - Middle click (also has a scroll capability) Button 4 - Thumb button 1 Button 5 - Thumb button 2 When I want to happen is the following: - When I HOLD button 4 and CLICK button 1, I want to skip to previous track. - When I HOLD button 4 and CLICK button 2, I want to skip to next track. - When I HOLD button 4 and CLICK button 3, I want to activate pause/play media key. - When I HOLD button 4 and SCROLL UP button 3, I want to increase volume. - When I HOLD button 4 and SCROLL DOWN button 3, I want to decrease volume. - When I HOLD button 4 and CLICK button 5, I want to mute all sound. Additionally, because I find it hard to let go of my mechanical keyboard, I would like to get some keys remapped on it: ⌥2 => ⌥V ⇧7 => / Z => Y Y => Z The operating system that I'm using is macOS High Sierra.