You could try a different prop, but I really dont see the need. Just keep it simple and use what comes with the kit to start out.
I have flown the Super Star EP that one of my trainees had bought just to goof around with and it flew pretty well. One thing I remember about it is that the motor wont last you very long, its a simple brushed motor. They are cheap, cheap so pick you up a couple of extra motors, you wont regret it. For the cost of 3-4 brushed motors that will probably only last you 15-20 flights each,,, you can get a brushless that will virtually last forever.

This Super Star EP setup isnt really worth upgrading to Lithium Batteries since there is no need to save weight (unless you want to double or triple your flight times), but again I will tell you that if you are going to keep it and fly it often, it will be well worth your money to pickup a brushless equivalent.

On the subject. I use lithium batteries in all of my airplanes now. Every single one of them,, Lithium Ion AND Lithium Polymer. They are very reliable and very stable when handled correctly, just like any other battery,,, if you mishandle it it can be dangerouse. No reason to be afraid of them. I have HUNDREDS of flights on my foamy Lithium Polys and at least 100 flights on the lithium ions in my 37% Ultimate and I have recently installed them in my newest pattern plane. Respect them yes, fear them no... no.... NO. They are superior to NiCad and NiMH in every way when it comes to performance. They weigh 1/2 as much as NiCad and NiMH and you get MUCH longer run times and much more efficient output from Lithiums than you do from Non Lithium batteries of "equivalent" size and voltage. Case in point, I can get 4 flights on a 2200mah NiCad battery,,, I can get 12-20 flights on a 2200mah Lithium Ion battery.
They are EASY to charge and very safe but LIKE ALL BATTERIES you have to use the correct charging method.

If or when in the future you want/need to go Lithium when you upgrade to a plane where weight and performance is really important,,,,just do your homework, get the right charger for the job (I use an Apache 2500 ($50) and a Triton Charger ($125) ). I have never had a Lithium pack get warm during a charge,,, much less explode or spontaneously combust.