They seem to me just fruits.
Here in South of Italy or in islands they often make fruits.
It could seem a parasitic fungus (Exobasidium rhododendri), known here as "afloat Rhododendron".
click for fungus
This parasitic fungus, however, is growing on the leaves, branches and any other part of the plant.
Your "balls" come right from flowers faded. So they seem really fruits.
The leaves seem suffering from Phytophthora ramorum see here
Camellia symptoms are limited to leaf spots, which can vary in size from a half a centimeter in diameter to covering nearly half the leaf, depending on environmental conditions. Lesions are usually on the leaf tip or leaf edge, and can be surrounded by diffuse margins or thick black zone lines. Plants will drop their infected leaves, and the lower part of the plant can defoliate.
Then: less water, shadow, "few fertilizer" for acidophilic plants.