I wanted that sort of complex multi-part clarity and sound going on that you get with some of those Tom Petty arrangements
I love Tom Petty and really admire the arrangements. Honestly, I think you're well into that territory. All you need is some tweaking on levels and maybe some EQ carving so that everyone has their own turf, at which point I think your arrangement is going to shine through.
Once you have the levels a bit more balanced out, you might look at each guitar and keyboard part and give some thought to which chunk of the frequency spectrum it should "own." For example, if the signature sound of one guitar part really lives between 700 - 800, then maybe you set your Q wide enough to highlight it and give it a little 1 - 3 db bump. Then take that same range and do a corresponding 1 - 3 db cut on the other guys in that sonic real estate (other guitars & keys). Then go to the next instrument and figure out where that one lives, rinse and repeat. That will cut out some mud and give clarity to each part without castrating them.
“hey listen to this bassline! But also to this guitar and this guitar and this keyboard and these drums!” when really you need to find a focus.
Yeah, I grapple with that sometimes as well when there are several instruments / parts in a song that I fall in love with. The analogy I use is a spotlight. Focus goes to where it's shining, and it can only shine on one thing at a time. On the hook it might be the guitar part, on the verse maybe it's the vocal, the bridge might be a rhythm section build up, etc.
Of course, I want everything to be cool, but it's like that line from the bad guy in The Incredibles - "When everyone's special, then no one is special."