Can I have some help understanding ritual path spell effects?

[Boyboy180]

So, I've read that some "effects" of a spell don't need to be paid for but I don't know how far it goes.

I've read that using strengthen body or destroy body to alter stats (AKA: Using lesser strengthen body to give +30% strength) doesn't require altered stats as it's built in to the strengthen body effect.

Does this also go for damage?
If I was doing a lesser destroy body effect to do 2d damage in a setting where that was normal hand-held weapon damage, would I not need to add extra mana for damage? Additionally could I then add more damage on top of that even without a greater effect?