In the Chicago central area, the best non-road ride is the Des Plaines River Trail. Around o'hare it is dirt, but turns into a small aggregate gravel as you go north. 35c+ tires work best and you can get away with a threadless all around tire. It is on a flood plain that floods often.
There's also a trail you can pick up in Evanston that follows the Metra line, but this is boring. Out west, there are two trails that run from the near west burbs to the far west burbs. These are straight as well.
There are two gravel rides at the beginning of the season - Barry Roubaix and the Dairy Roubaix. The Dairy I think is treaded tire/light mud and the Barry is slick tire.
Crank - The FSA is something short of s***, but not s***. The FSA rings are s***. Praxis and Shimano (Ultegra/Dura) makes a nice set. Maybe go 50/34 unless you're touring with bags. 1x is good, but if you already have 2x 105, I'd just get Ultegra 50/34. It'll handle dirt days and road days better than a 1x setup.
Wheels - I have a do-it-all CX bike. I have a set of Stans Grails for the dirty days and a set of DT Swiss R32s (ER1600 now??) for clean days. Is your bike Specialzied SCS rear hub? If so, this changes your options. Looks like it's 12x142. Keep in mind you'll need/want a cassette, tires, tubes(maybe).
For "cheap", borderline aero road wheels: DT Swiss ER1600 https://www.dtswiss.com/en/products/whe ... spline-32/
$400 for the set. Adapters for everything (that you can resell on ebay for about $75 total). DT Swiss that a 240lb dude can do 6" drops with them. You won't see better road performance until you start paying for Carbon aero rims. You won't see much cheaper that are better than you stock rims. Fulcrum 4 DB is another option in the same theme, but any replacement spokes are harder to get.
Tires: That Specialized 42c tire isn't bad. You can change them, but it won't change your life. They should be 127tpi, soft casing tires. I see about 1mph difference between my 25c GP4000 fast-day-to-day tires on the rims above and my Clement 35c USH tires on CX rims. You'd probably see the same difference between your tires and your best day-to-day road setup. If you want a fat tire road setup, you're looking at Gravel King or Compass. I'd just keep the Sawtooth on those wheels and get the road set. When the Sawtooth wear out, then decide how much mud/sand you're dealing with. If none, get the slick fat tires. For road tires, get some 28mm tires, you can do some hardpack on those.