Witch Hazel
The shrub you are referring to is likely the "Senna" genus, which is native to South Asia. Senna plants are known for their medicinal properties, particularly their use as a natural laxative. They have distinctive yellow flowers and are commonly used in herbal medicine.
Yellow
Acacia.
Barberry
The Chinese most commonly use the bud of the flower in their medical practice, in other countries it is mostly the flowers and leaves that are used for their healing properties.
Yes
Cytisus or broom.
Japonica
Jasmine
In sub-tropical areas, allamanda cathartica is a soft shrub with clusters of bright yellow flowers at the tips of twigs. Not strongly fragrant, at least not in my garden.
A rose plant is classified as a shrub. While some herbs are plants with aromatic leaves used for food or medicinal purposes, roses are considered ornamental shrubs due to their woody stems and flowers.
Sounds like a Berberis.