Remove the PA2 from the receiver, since you're already flying trainers. Remove/do not install the wing junk, on the leading edge or screw on the underside plastic pieces. You'll want to get 6 minute epoxy and epoxy the tail in place, like all normal planes do. Use the bolts only for alignment.

The one bolt that holds the main wing on, is held in place by a plastic piece that is fastened by two small screws! This is a problem area of weakness. Epoxy that as well so you never lose the wing in flight.
Break in according to the instructions. ABC engines are resilient. You should not 4 stroke a ABC engine in break in. They need to expand and break in richer than a ringed engine, so don't 4 stroke it but a couple times, for 10 seconds, as it states. I'd fly it on the second tank, I've done this for decades. Level flight and less than full throttle, is all I did.
Remove the needle valve limiter.
If you can avoid 16% fuel (for 4 strokes) and have anything else on hand, just use the 18%, as the nickel liner is not as durable as true chome sleeve engines.

These fly OK. Not really my first choice in a trainer, but free, why not?

Cycling 600mah nicad batteries on a radio that old isn't a good idea. You can cut the battery out. Save the connector, solder it on to the new battery pack.
Xacto knife the plastic cover and pull those batteries loose, and trim out as much as the plastic covering to the battery as you can. Replace that battery. Many affordable batteries on Ebay and nimh is better, 2000 mah is common. For best results, discharge the battery on arrival completely and then fully charge it after. http://www.ebay.com/itm/New-8-Cell-F...UAAOSwj2dXjTaZ
Nothing is worse than sudden battery failure in the plane or in the radio and you simply watch it auger into the ground.
You can also epoxy the main wing halves together than just screws alone on the plastic wing joiner.

Epoxy on stab/fin and wing really makes the plane more dependable and lowers the risk of parts falling off, and they're known to do that after awhile.
The engine is ball bearing and can go into your low wing trainer next. If you flew a full hour every weekend for 3 years, the engine would still be good.
Any trainer becomes more aerobatic if you pick up some fiberglass and resin, and take the dihedral out of the wing, lay it flat and glue the wings together, and then fiberglass the joint for strength. Discard that plastic center piece. You can install a wooden dowel in it's place, just drill a hole and epoxy the dowel in place. You can eye ball the angle and get it right. Reinforce the dowel again with a layer of fiberglass and epoxy around it. The plane performs better without the dihedral, flies inverted better, banks into turns and rolls easier. You can modify this plane to bring your skill level up and improve the flight characteristics from the trainer level. The silver monokote easily comes loose after a few flights, so tack that down better with an iron and perhaps some trim solvent from tower as well.
See photo attached, got one of these currently, your lucky day.
The epoxy can be thinned with denatured alcohol and you can get a small epoxy brush and reinforce the firewall and bulkheads, as you can see, the fuselage is built with a minimum of CA glue. Fuel proofing is done this way, or finish resin also works having a thinner consistency for brushing it on as compared to the thickness of regular epoxy on that chore. The life of the plane extends considerably doing these things, as well as helps it survive rougher landings.
Personally, if I were you, I'd take that plane if it's in fact unused, and sell it on ebay, and use the funds for a more advanced model. Check out Airborne Models Sky Raider 2. They're $129.95, the control surfaces are already hinged, build time is 3 or 4 hours, and the flight characteristics are a lot more enjoyable.
How many trainers does one man need? It's a stepping stone to better things. Just my opinions. http://ecsvr.com/abm/shopexd.asp?id=2926 Tailset is also a screw together arrangement, but again, just to hold it in place as you reinforce the tailset with epoxy, always.