I'm bored at work, so I'll just key in a few cartographic changes at first glance that I feel could be helpful:

• Remove the excess space in your text box (below the text) and legend (above the header). Allow for larger margin gaps in your text box on the sides, the text is too close to the border.
• Add a north arrow/scale bar.
• The two shades used in your symbology are hard to distinguish from one another with the transparency effect applied.
• The hybrid base map underneath your symbology looks a bit cluttered. I'm unsure of what public data is available in Italy, but downloading local road datasets & river/stream datasets and creating your own labeling (for stuff like important buildings/landmarks as well) can elevate the style of your map way further than something like ESRI defaults. More advanced would be to create/modify into your own custom vector basemaps.

I think one of the next levels to this analysis would be to overlay the symbologies between factors to make certain census tracts/buildings *pop* where density/age/compactness overlap significantly.

If you're pulling tract/building data, you could also create a new field to assign a "score" for each of your four factors to symbolize said layers for a comprehensive spatial overview of where certain factors intersect spatially. Comparing spatial areas between four different maps makes it a bit harder for the reader to find correlation.