Hey MattioliCo, I didn't tend to get detailed to confuse you (you know, sometimes this can effect the engineer in a negative way too) but seems you prefer opinions as much as possible.
About using a limiter: the most common mistake with using a limiter is to go insane with the compression. By insane I mean most mastering engineers agree that more than 2-3 db of reduction is too much for any mix.
Before a limiter you can compress peaks or mix, use hard clipper plug-in or clip converters if you have high-end. Also using 1 limiter isn't a rule, sometimes lightly used 2 limiters get better results. As you compress, hear whats damaged (there's always a damage somewhere) or changed and try to fix it-if you can't fix it then you reached your amounth of loudness. Also what I wrote here is truly harder to do than it seems. So its never a mistake to get you mixes mastered professionally (and its not that expensive, make a search).
About mix balance: There are arangement issue's thats for sure. But also what I feel is when the song is mixed, every sound was focused to sound best by itself but the interaction between them was missed.
Its hard for me to give advices about this without trying some stuff in the mix but try focusing on placement (in a 3d way). I mean not always every instrument must sound great when played alone. You can kill the highs, duplicate tracks, send more reverb etc. to the individual insturments in different amounths to make them sound in the same structure (but still keep all the individual sound sources being heard).
I know its going to take a lot of time to do that but if it helps, set a transparent compressor (with no agressive settings) to the mix buss and then start working-you'll acheve depth easyer that way when the compressor is bypassed (but I can't say this can work for everyone).
Again, seems the arangement won't be helpful to you so don't go hard on yourself
exept for the limiter setting, the mix is to me is already acceptable in many ways...good luck!