I'll address both here, then. Not ever being hit is game breaking, even if you do not "over-rely" on attack rolls. This is because it would take a serious divergence for attack rolls to NOT be the primary method of reducing hit points. A DM would have to go out of their way to select monsters/NPCs that do not rely on attack rolls, and there are very few that do this. Even dragons, the titular creature of the game, rely primarily on attack roles to reduce hitpoints. So the other path would be to reduce the impact of combat as a resolution mechanic, which is another departure from the baseline. No problem in choosing to play that way, of course, just noting that given the wealth of intended play examples in the official products over all editions, combat is THE primary conflict resolution mechanic. And, again, within combat, attack rolls are THE primary damage vector.
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