RE: Landing on a Grass Strip
A prop saver can help if your plane doesn't have a cowl.
Or, large, thin wheels. At least 3" in diameter. Those that come with the Slow Stick and E-Starter work very well in grass up to about 4" tall.
Cut the motor just before landing so the prop isn't spinning at touchdown.
If you have break off on your ESC then turn it on. That will stop the prop and will also improve you glide ratio.
Bill