Video thumbnails
Taking the "YouTube Thumbnail · High CTR" template as an example: about 12 credits on Nano Banana 2.
The credit prompt before each generation is authoritative; it changes with model, resolution and duration.
Video topic · The hook to emphasise.
A single generation usually lands between one and a few minutes depending on model and resolution; several can run at once, with the limit set by your plan.
Yes. Any shot can be re-run with an edited prompt or a different model; what you already generated stays, and re-runs are charged at their actual cost.