"Why is my drone not stable while flying?"に関する回答There are many reasons that could cause unstable flight. Your best bet is to go through the solutions provided on the Troubleshooting Guide.
"How to fix broken propellor?"に関する回答The Propeller and Gear Replacement Guide will clearly demonstrate how to replace your propeller. I hope this helps!
"Drone will not charge, even with new battery."に関する回答Refer to the Troubleshooting Page to find a fix. It could be because of damage to the drone itself, in which case the main board may need replacement.