The higher the compatibility, the smaller the file. What is your General > Compatibility setting? What is the text resolution setting? Do turn off Embed Thumbnails and turn on Optimize for Fast Web View for smaller files.
If those illustrations are vectors, they are controlled by the previous resolution settings. If they are raster image (and illustrator files can have images inside as well as raster effects), I'd go for .JPG over .ZIP. JPG is a format designed for archiving images in a small container. Play with the Image Quality to see how low you can go. Note that there are three separate settings in here: one for Color Images, one for Grayscale Images and one for the rarely used Monochrome Images. You only need to mess with the ones that pertain to your document and ignore the others.
Finally, consider subsetting your fonts. For example, if you just use a few symbols from an ornamental font, subset them instead of including every single character.