The 205/55r16 is the standard i30 size, likely 100s of thousands of i30s at this point are getting around with no stability issues using this size.
Unless you go the cheapest tyre, the road noise should decrease. You'll find your economy should improve.
Wider tyres offer better traction and braking, on the road, however you aren't drastically changing that so it will just be a matter of adjusting to your new tyre.
If your dirt road gets muddy, the skinnier tyre is superior.
You're driving a passenger car not a beefy 4wd that has big chunky rubber, the skinnier tyre has less contact patch to slip on loose gravel.
Having lived on a farm with many dirt roads of varying surfaces, and having multiple vehicles with skinny & wide tyres, skinny > fat on the dirt unless you're running all terrains with reduced pressure.
The 205/60 offers the same but with a bit more comfort. Won't have as much impact to fuel economy as a larger tyre but would be worth imo.