As for repairs...
Axle - you're up for a new axle. Check the condition of the cone nut and their bearing surfaces - they may be okay but any dents or pits and they're better-off being replaced.
Wheel - Inspect the wheel's cups too - they are much more expensive to replace so minor damage to bearing surface you may choose to accept.
Bearings - Do just replace all the bearings in the wheel too - even if you saved them all they will be worn. Ball bearings are cheap.
Derailleur - needs more inspection but I'd replace it. The bent bits may be straightened, but the missing limit stop for the large cog is going to be fiddly. You could braze or solder something in to act as a stop, but any repair could fail repeating this whole problem - not recommended.
Transmission - I suspect the chain and cassette will be okay, but do clean and inspect them for damage.
Spokes - again inspect. Its possible for the Drive Side spokes to get munched at the bend where they enter the hub, leading to premature spoke failure. I'd remove the cassette and any plastic protector, clean down and look closely at the elbows. Decide if damage is minor scratches or significant gouges, and replace the worst spokes first.
Frame - your derailleur hanger looks bent in the photos, but hard to know. Its a replaceable part so consider just buying a new one. They're not cheap, but they are much cheaper than a replacement frame.
You can do this yourself with time and effort, and its quite rewarding to fix it yourself. Or you could involve the borrower to help, depending on the social situation.
Once the repairs are done, you will need to fine-tune the rear gears and limit screws to ensure they're in the right place to stop this happening in the future.