How much are you willing to spend on upgrades ?
You mightn't see much on improvements with some upgrades.

I see from another post that you've ordered some Continental City Contact Tires which looks to be the same as the Continental Comfort Contact Tire, maybe they changed the name for the new models, you also enquired earlier about putting 26"x1.0" tires on the bike.

How much off road riding will you be doing ?

Will you be swapping tires ?

If you'll be mostly riding on the road you should definitely look at buying some clipless pedals and bike shoes.
With some models of clipless pedals you can adjust how hard or how easy it is for the shoe to release from them, there is also different cleats for these pedals too, some will release easier then others.