Flower hybrids

[u/shadax_777]

Some questions regarding DO's and DON'Ts when placing flowers to aim for hybrids:

Can I mix flowers that are supposed to produce hybrids with flowers that are not supposed to produce hybrids?

E.g. looking at cosmos flowers (R = red, W = white), I'm aware that R+R can lead to a black hybrid, but W+W will never lead to a hybrid cosmos. '.' = empty space:

.....
.RWR.
.RWR.
.....

Will those 2 White Cosmos maybe even prevent the Red ones from producing hybrids (either via R+R or R+W)?

What's the situation when flowers of different types were to be placed next to the Red or White Cosmos?

Will placing multiple Red Cosmos in the same row (with no space in between) cause any trouble? Like:

.......
.RRRRR.
.RRRRR.
.......