You summed it up.
Yes, you can close the doors gently, or normally. Sometimes if I close the doors normally I still hear the soft-close motor activate. I can't believe it hurts it any to close them normally.
I like it actually, and its better for my kid to close the door from the seat and have it ensure it latches all the way.

The only disadvantage I feel is more mental - I have gotten used to closing the door softly, and like doing so now... but EVERYONE you let ride in the car constantly slams the doors shut which is unnecessary, and you just notice it even more if you have the feature. I don't feel like asking everyone to close the doors gently.

I never looked into disabling it; I don't want to. Maybe someone else here can address if its a matter of pulling a fuse or what.

Totally personal preference. Look, these cars are FULL of little features that can all go wrong. Just add these to the list. If you are that worried about them failing then avoid them.
Hope this helps.