Thats a lot of rust.
Yup, forks are solid rust, wheels are nappy, frame is very rusty, front brake hub is not mounted correctly, missing air box, . I dont think its worth $350 even running. Pass on that bike.
You can find a Puch or tomos for under $200 all the time.
Not really, they exist but you need to harp craigslist / facebook and call the seller quick.
Like heres a scrap pile for $350 (minus the ebr forks of course).
Nope, thats a magnum. Good luck finding another magnum for cheap. If there are some for less people are blowing up the sellers phone and lining up at this door. Just because you found one for $50 10 years ago doesnt make all magnums worth pennies.