Is it save to replace and old fuse panel with a new breaker panel if wiring is all 14-2 wire in the wall

Save or safe ?

In a word... yes. But you need to use the correct size breaker for 14 ga wire, which is 15 amp. Always use the correct size breaker for each circuit. If you add more circuits, then you can add the appropriate breaker to correspond with the wire used.

Sure it is safe. You are not planning to do this yourself, are you?