The shampoo does have a small scent:

Its sensory formula, with the delicious, natural scent of oat milk and its creamy foam, is just as effective as a liquid shampoo.

I don’t have long hair, but I find that it behaves like a liquid shampoo. But I can’t say how it would exactly work on long hair.

En tout cas, j’en suis très content :)

No, it’s this one (the site exists in English if needed). What you linked is the conditioner.

And yes, you use it like soap, but directly on your hair. It very quickly produces “soap bubbles”.

I’ve not used liquid shampoo for about 3 years now.

I only use solid shampoo, which currently is the one from Fer à Cheval.