Hey guys and gals!
It's been a LONG time (15+ years) since I flew an RC airplane. Long story short... Life happened but now my 11 year old daughter is interested in at least trying to fly my RC airplane. I'd like to expose her to RC and if she's not interested in it beyond that, I'd like to get my RC airplane and equipment in good enough condition to donate or sell cheap to someone starting out.

I have a simple SIG Kadet LT-40 that I built from a kit with a cutting edge (at the time) JR XF631 radio. Everything is still in great shape although untouched for 15 years. I'd love your input on where to start to get this back in running condition. The engine was stored oiled and still turns over just fine. Here are some questions:

1- The google hasn't given me a clear winner on where to buy new batteries for the transmitter or receiver. The JR website was no help either. Any recommendations on where to look first?
1a- Am I crazy to try to use the old radio for an endeavor I may not be in to very long at all?
2- What should I be looking for to essentially "preflight" this thing other than checking over servos and getting the engine running well. Any "gotchas" I should be on the lookout for?
3- Does CA glue or the covering itself degrade for an airplane that was stored indoors and out of sunlight?
4- How long does fuel remain usable? I've still got an opened jug of Cool Power that I'm sure has gone bad but I was curious how long you guys keep opened jugs of fuel before you would no longer use it.
5- There are lots of options I see online for computer training software to get my head back in to flying RC. Which ones do you guys recommend? Bonus points for one that might still connect to an antique XF631.

Thank you VERY much in advance for any answers/ideas you might have!

Cheers