Gabriel wrote:

Did anyone try to raise them in containers with 100%
organic treatment ?

Sure. They do just fine if you pick sound, disease resistant roses. You
can effectively fertilize roses with fish emulsion and other organics,
including blood meal and fish meal as well as composted manures. It's
just more work. And as for pesticides, many roses are just fine without
them. But you must choose carefully.

If they get sick, is there an increased chance
they will spread the disease to the other plants as well ?

There's a chance, but the other plant would have to be a variety
susceptible to the same diseases. Fungi that infest roses are
generally strains that are rose specific, but there are undoubtedly
exceptions.

Since containers dry very quickly, does that increase disease
casualties ?

It can, if the rose is severely stressed. Water polymers are highly
recommended for roses grown in containers in dry climates.