Vercure is not part of your rotation.

[Fortune_Cookie]

I haven't gotten Vercure yet, but my plan was to only use it on myself (to make the Healer's job easier when I'm bad), and on the Healer (cause from my healing experience a lot of times I tunnel vision on the other party members health and forget about my own health, so I figured it'd help other healers).

would I be doing it wrong?

If you care about efficiency, then yes. Vercure is an emergency tool to be used when the healer(s) cannot keep up for whatever reason (e.g. because they're dead). Using it just to help the healer when the healer doesn't absolutely need that help is a waste of everybody's time. If you took some unnecessary damage, try to dodge better next time, but don't compound the issue by wasting dps.

Wanting to help your party is of course the right instinct, but outside of real emergencies the most effective help you can offer is to make stuff die faster.