Outlaw 525 irs questions

Hey guys, I just sold my hawkeye and am looking into sport quads. Im completley new with them and don’t know much about them so i have some questions.
Im looking at getting a 525 irs because im still going to be doing some trail riding but I still want the sport quad.
What should i be looking for/watching out for when buying?
Do you really need to change the oil every 10 hours?
What kind of oil should I use?
Is there any other regular maintenance other than changing the oil?
Why do you see so many of them for sale with new top ends? Is it because they blow up easy?
Thanks