I listened to the several mixes. And I agree it's moving in a good direction.
The key to getting good at mixing is a cumulative process. The more you do it, the better you get. In addition you need to study and analyze the things you do that work and don't work and why.
Robert pointed out doubling the electric and panning it opposite. I use that a lot on acoustic guitar and it certainly puts a nice solid, wide bed in place for the rest of the tracks. Shoot for a nice, clean, balanced mix. You can always make it louder later.
Several of my rules of thumb include:
Get good input levels and have the recorded wave that is displayed in the track somewhere around the 50% level. That's usually plenty sufficient. More is OK as long as nothing is clipped or over. Less is often OK.... 50% is just my target zone. Too high and it simply means you will be pulling the faders down more in the final mix. Too low and you're tempted to push above 0db and use FX to get the levels up high enough.
Record mono things in mono. Rarely do you (I) actually need a stereo track in the mix.
Use busses. More then once I have set up a "band" buss to route all the band through..... rather then go back and lower the levels to match and balance, I set up a buss to do that.
Keep the individual tracks out of the red. (basic rule of thumb for avoiding distortion and clipping)
Use FX sparingly. My tracks are mostly empty with a few exceptions and that's usually an EQ. If you find yourself grabbing and using a compressor or Boost11 to bring a track up....ask yourself WHY? It might be better to turn the other tracks down...... go back to "Use Busses"....
Mix, mix, mix and mix some more. Your stuff, other people's stuff, and then remix some of your old stuff starting from scratch. It's amazing how, after a few years, if you go back and remix the old stuff, you will see how far you have actually come in that time.....
BTW: the song is a good one.... so keep working on the mix..... but don't obsess or burn out on it.