This may be a question that can't be answered but I figured it may be a little fun to try anyways. I know the rules that are established about the dragonballs:
- 1 (original earth) /2 (later on earth) /3 wishes (Namek) depending on which version you have.
- Wish can't exceed the creator's power
- If the earth dragonballs then can't make the same wish twice
So in rewatching the series with my wife recently, when they are on Namek she asked if they could just take the balls into space to hide them which is a great question IMO. Freiza, or Vegeta for that matter, could have just parked their space ship floating over Namek or on some moon or close by planet and had it come get them every so often to deposit found dragon balls, or in Freiza's case where he doesn't need air to breathe he could just fly away with them.
So are there any rules about the dragon balls leaving the planet to which they were created on? Would they turn to stone? Would they just not work?