Thanks to xfigox, Cheez and kongwee for the time taken to listen to my track and also jotting down some notes for me!
Regarding the mastering, I used iZotope's mastering software for a quick all in one processing on my track post-mix. So, I don't really think stereo widening and harmonic excitation is really much of a problem. Too much of it would definitely be jarring for the ears. That being said, I feel the stereo positioning of my instruments weren't very well done which may have caused some of the problems you guys have mentioned. The right electric guitar was panned too far right and sort of removed the idea that it was a rhythm guitar.
I agree with Cheez too, that I needed to focus on which instruments I should highlight at each portion of the mix. I think this stemmed from the fact that I've worked on this song for about a month, which made me know all the intricacies of the song which first or second time listeners would definitely miss. So yeah, I'd work on this too. I'd probably outsource my mastering to someone else once I get enough songs to release an EP so I would have a fresh take on the tracks. But generally, I really do have to brush up on my mixing. Currently reading many guides and tutorials on it so yeah, hope it improves.
Regarding the effects. I used a general plate reverb for my vocal tracks to have that pop sheen over it but didn't really play around it. I sort of chose a preset and left it there instead of tweaking it to enhance my vocals. So I'd really have to work on being a perfectionist and stuff. For the compression, I don't really agree with Cheez in that I think instead of the lack of compression, I've used TOO much compression. The ratios were definitely out of balance and I think I've compressed the signal so much that I've removed most of the dynamics of my voice. As for the suggestion for parallel compression by kongwee, I'd definitely look into that thanks for the tip!
So yeah, just some notes for the stuff I've learnt from your comments. Although I didn't quite agree with all of them, it did force me to re-listen to the track focusing on certain things which allowed me to learn from my own mistakes myself.
Putting the production aside, I hoped you guys generally enjoyed the song for the music itself. This is a general sound that I've chosen for my project; music that I like.
Just to let you guys know, I won't be re-releasing this track. Instead I'm going for a 'let's look back at what I've done and I see the progress I've made' kind of thing. So just look forward for my next track! Hopefully it'll be a step in the right direction.