Answer to your first question: No. The battery is fine, the stupidity in understanding that Li-ion batteries must never be fully discharged is the only catastrophic failure here.
Why can't I down vote your post? :(
PS: Don't buy any RC model (or diesel engines!), they all suffer from the same "catastrophic failure".
What about diesel engines? I have a diesel, have run out of fuel (clogged filer), have had air in the system - bled it out, was dangerously low on radiator fluid but no ill effects.
All that over the span of ten years and I still drive it actually the engine is the best part the rest of the truck is falling apart around the engine.
Add to those no spark plugs, no spark plug wires, no distributor, a more durable engine design, higher efficiency compared to a gasoline engine.
Why can't I down vote your post? :(
PS: Don't buy any RC model (or diesel engines!), they all suffer from the same "catastrophic failure".