Here are a few pointers for avoiding calamity on the court.
Basketball backboard clearance
When considering the safety of any basketball hoop, the primary issue is the overhang of the basketball hoop from the basketball pole. If you expect some competitive play on your basketball hoop, and any basketball hoop should see some tough games in its lifetime, shoot for about 3 feet of overhang from the basketball pole to the bottom of the basketball backboard.
Unfortunately, basketball poles with distances of up to three feet between the pole and backboard can get a little pricey. You'll find cheaper ones with distances as low as 18 inches. This creates much less strain on the pole and allows for cheaper materials. There is a solution, though.
Different varieties of basketball pole pads are available to protect those driving hard to the hoop (and perhaps a bit recklessly). For as much as $200, you can get safety basketball padding for street hoops, which just means a broader, more protective layer of padding that extends several feet in width instead of just covering the pole. This may be excessive - the kind of thing cities purchase to prevent lawsuits from public courts. You will probably be best served by a thinner basketball pad that just covers the pole. They are affordable as well as easy to install and keep clean.
If you're expecting some larger folk to be testing out your basketball rim, it is well worth it to get a flexible rim with covered springs. This go by various names, the most common is "breakaway rim."
That about covers it. We wish you happy shooting, with the reminder that no piece of safety equipment will compensate for careless play.